Let’s remember the key traits of the Trinity. According to the Athanasian Creed,

The Father unlimited; the Son unlimited; and the Holy Ghost unlimited.…
So likewise the Father is Almighty; the Son Almighty; and the Holy Ghost Almighty. And yet they are not three Almighties; but one Almighty. So the Father is God; the Son is God; and the Holy Ghost is God. …
And in this Trinity none is before, or after another; none is greater, or less than another.…

About Jesus, it says:

Perfect God; and perfect Man …
Who although he is God and Man; yet he is not two, but one Christ.

Okay, okay, I get it. Three persons, all equal. None greater than another. Jesus is unlimited, almighty, and perfect.
But look to the Bible for confirmation and you’ll find that unlike the clear definition of monotheism in the Koran, the doctrine of the Trinity is not clear. It took almost four centuries to congeal.
Consider some Bible verses that challenge the Trinitarian concept as defined in the creed above. First, verses that portray Jesus as an ordinary person who didn’t know everything, who wasn’t completely on board with the program, who got impatient, and who spoke to God as you or I would.

When Jesus heard this, he was amazed (Matt. 8:10)
[Jesus] turned around in the crowd and asked, “Who touched my clothes?” (Mark 5:30)
[Jesus prayed,] “My Father, if it is possible, may this cup be taken from me. Yet not as I will, but as you will.” (Matt. 26:39)
Jesus cried out in a loud voice, “My God, my God, why have you forsaken me?” (Mark 15:34)
Jesus often withdrew to lonely places and prayed. (Luke 5:16)
You are looking for a way to kill me, a man who has told you the truth that I heard from God. (John 8:40)
[Jesus said,] “I am ascending to my Father and your Father, to my God and your God.” (John 20:17)
Faithless and perverse generation! How much longer must I be with you? How much longer must I put up with you? (Matthew 17:17)

Verses that state that only God has certain traits or abilities.

No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father. (Matt. 24:36)
[Jesus said,] “The most important [commandment is:] The Lord our God, the Lord is one.” (Mark 12:29)
God, the blessed and only Ruler, the King of kings and Lord of lords, who alone is immortal and who lives in unapproachable light (1 Tim. 6:15–16)

Verses that portray Jesus as inferior to God.

“Why do you ask me about what is good?” Jesus replied. “There is only One who is good.” (Matt. 19:17)
[Jesus said,] “the Father is greater than I” (John 14:28)
The head of every man is Christ, and the head of the woman is man, and the head of Christ is God. (1 Cor. 11:3)
The Son himself will be made subject to him who put everything under him, so that God may be all in all (1 Cor. 15:28)
You have been raised with Christ, set your hearts on things above, where Christ is, seated at the right hand of God. (Col. 3:1, see also 1 Peter 3:22)
There is one God and one mediator between God and mankind, the man Christ Jesus (1 Tim. 2:5)

Ever-nimble Christian apologists have had two thousand years to handwave responses to these. Perhaps they’ll argue that we’re seeing the limited human side of Jesus here, not the God side. Or that other verses can be brought in to bolster the Christian position. Nevertheless, there is no evidence for the Trinity coming from the Bible. It was invented by theologians centuries later.
The simplest explanation is that the Bible is a collection of books from authors (many unknown) who had similar but not identical religious beliefs, which has been modified in unknown ways over the centuries, and which has no more accuracy in its depiction of the supernatural than the Iliad.
See also: 

• “Colorless Green Ideas Sleep Furiously” as Reasonable as the Trinity
• What Does “God” Mean? The Answer Undercuts the Concept of the Trinity.

It ain’t supposed to make sense; it’s faith. 
Faith is something that you believe 
that nobody in his right mind would believe.
— Archie Bunker

(This is an update of a post that originally appeared 6/14/13.)
Photo credit: Samuel Livingston, flickr, CC
 

Why can’t Christianity think of a better name for its god than “God”? A god named “God” is like a cat named “Cat.”The fourth name of God
While we’re talking about names, if Father, Son, and Holy Spirit are the persons, what do you call the union of these into one god? Shell, white, and yolk form an egg. Ice, water, and steam are three states of H₂O. Father, Son, and Holy Spirit form whom?
You need a fourth name. Do you call it “God”? That won’t do because the Bible tells us that “God” is the one who created everything, and that’s supposed to be the Father. The Father can’t be both the first person of the Trinity and the overall god at the same time.
Calling this union the Trinity would emphasize the separateness of the three and risk the heresy of Partialism. Father, Son, and Holy Spirit are supposed to form a single, unified who. Another problem with “the Trinity” is that’s an odd name for a monotheistic god. It’s a label, not a name. Call the three persons “a council of three” if you want, but that doesn’t make clear the unity like a proper name would.
That the Old Testament uses one name for God (okay, it uses several names—Yahweh/Jehovah, Elohim—but that’s a different issue) makes clear that God the Father was no Trinity. Without this distinction, it’s clear that there is no Trinity in the Old Testament.
Let’s see this another way. Consider this passage from Isaiah 45:5–6:

I will gird you, though you have not known Me; that men may know from the rising to the setting of the sun that there is no one besides Me. I am Jehovah, and there is no other.

There are two interpretations of this passage, neither of which supports the Christian interpretation.

• If Jehovah is a synonym for “the Father,” this means that he reigns alone (since “there is no other”), and we must discard the Trinity.
• If Jehovah is a synonym for “the Trinity,” then it makes nonsense of the singular pronouns (Me and I) in these verses and confuses passages such as “Then Jehovah spoke to Moses” (Ex. 40:1) or “After Jehovah had spoken these things to Job” (Job 42:7).

The problem, of course, is demanding a Christian interpretation of a Jewish text. There’s nothing confusing here from a Jewish viewpoint, and that was the intended audience. There is no Trinity, and the only god that exists is Jehovah.
Well, at least the only god at this time in the evolution of Judaism. It’s a little more complicated because Old Testament Jews didn’t begin as monotheists. The Old Testament documents their evolution from a kind of polytheism (that’s an aside that I explore more here).
Admittedly, one handy feature of the Trinity is that it gives Christians a way to reinterpret some embarrassing passages from the Old Testament.

Let us make mankind in our image (Gen. 1:26).
The man has now become like one of us, knowing good and evil (Gen. 3:22).
Let us go down [to Babel] and confuse their language so they will not understand each other (Gen. 11:7).

These are no problem if “us” refers to, not a council of gods as a careful reading of the Old Testament reveals, but the three persons of the Trinity. But if understanding God as a trinity were important, he would’ve made this clear from the beginning. Judaism’s evolution from polytheism explains this nicely. The conflation of “God” to mean both “the Father” and “the Trinity” reveals the Trinity as a clumsy later addition.
See also “Colorless Green Ideas Sleep Furiously” as Reasonable as the Trinity

Ridicule is the only weapon which can be used 
against unintelligible propositions.
— Thomas Jefferson

(This is an update of a post that originally appeared 6/12/13.)
 

Linguist Noam Chomsky suggested “Colorless green ideas sleep furiously” as an example of a sentence that is grammatically correct but logically ridiculous, but it is no more ridiculous than the Trinity.
The Christian doctrine of the Trinity claims one God in three persons. The Catholic Encyclopedia defines it this way: “In the unity of the Godhead there are Three Persons, the Father, the Son, and the Holy Spirit, these Three Persons being truly distinct one from another.”
Unity but also distinct? Three but also one? That makes no sense, so let’s go to the source and read about it in the Bible.
And the Bible says …
Though the Trinity is one of the most fundamental doctrines of Christianity, the Bible says nothing about it directly. Did Paul and the apostles define God in a trinitarian fashion? Nope. If the Trinity is essential to a proper understanding of Christianity as the modern church claims, the ancients’ silence on the matter makes clear that it is a later invention.
That’s not to say that one can’t use the Bible to form arguments in favor of various relationships between God, Jesus, and the Holy Spirit. Several interpretations competed in the early centuries of the church.

• Was Jesus merely a good man, adopted by God (Adoptionism)?
• Are Father, Son, and Holy Spirit just labels for the different roles of one being (Sabellianism or Modalism)?
• Was Jesus created by God and subordinate to him (Arianism)?

These are all plausible interpretations, justifiable with Bible passages, but they are heresies today. It took about two centuries for the doctrine of the Trinity to enter the debate (through Tertullian), and it took almost two more centuries of haggling for the doctrine to mature into its present form and sweep away its competitors at the First Council of Constantinople (381).
While still a cardinal, the man who would become Pope Benedict XVI was asked if he was bothered by many Catholics ignoring papal dictates. He said that he was not, because “truth is not determined by a majority vote.” But a majority vote is exactly how doctrines like the Trinity came into being.

See also: Bible Contradictions to the Trinity

Comma Johanneum
You know how I said that the Bible says nothing directly about the Trinity? For completeness, we should address this:

For there are three that testify in heaven: the Father, the Word and the Holy Spirit, and these three are one. (1 John 5:7)

The part in italics is called the Comma Johanneum (a “comma” is a short clause). The oldest and most reliable manuscripts do not show the Comma. It appears first in a few seventh-century Latin manuscripts and only centuries later in Greek manuscripts. Unlike much of the rest of the New Testament, it doesn’t appear in the letters of early church fathers, many of whom would’ve delighted to support their position with such a quote.
It is agreed by scholars to be a later addition to the original.
What is the Trinity?
Lots of analogies have been proposed for the Trinity. Maybe it’s like water, which has the three states of solid, liquid, and gas. Or like a person who can be spouse, parent, and employer. But this is modalism—God acts in different modes at different times.
Okay, then maybe it’s like an egg, which has shell, white, and yolk. Or like time, which has past, present, and future. Or like the Borromean rings above—three unlinked rings that make a linked whole only when all three rings are present. But this is Partialism, the heretical claim that the three persons of God are three separate parts.
Even world famous apologist William Lane Craig commits this heresy:

[The Trinity] is the claim that the one entity we call God comprises three persons. That is no more illogical than saying that one geometrical figure which we call a triangle is comprised of three angles. Three angles in one figure. Three persons in one being.

Given the clear history of conflict on this question and the many discarded explanations, you’d think that heretical analogies wouldn’t be offered.
Many careful Christians simply say that it’s a mystery and admit that we can’t understand it. Contrast that with the monotheism celebrated by Islam. The shahadah, the basic creed of Islam, says, “There are no deities but Allah, and Mohammed is his prophet”—simple and unambiguous.
A few questions raised by the Trinity doctrine
Instead of the convoluted and unintelligible Trinity, why not simply embrace the polytheism? My guess is that first-century Christians so valued Jewish monotheism that this tenet couldn’t be dropped. As the stature of Jesus increased over time, from a good man adopted as messiah by God (as told in Mark) to a being who was there at the beginning (John 1:1), they were stuck with fitting the square peg of the divinity of Jesus into the round hole of monotheism.
Why not then have a duality, Yahweh + Jesus? The problem is that two is the number for male and female, which was not the symbolism they were going for. Perhaps the Holy Spirit, initially just a bit player or merely a synonym for God, was elevated into the Trinity. And even this is flexible. While the idea of Mary as Co-redemptrix is not Catholic doctrine, it has threatened to become so at various periods in the church’s history.
And now let us close …
The typical Christian response to a contradiction is to find a way to make both claims true. This is never clearer than with the Trinity. The Bible says that there is one god, but it also says that Jesus existed since the beginning of time. So they must both be true! But what first-century Christian would rationalize this with the doctrine of the Trinity?
Or, take this from the other direction. Explain the Trinity to first-century Christians and ask if that matches their understanding. If you imagine that they do, you have a new problem: why the vitally important doctrine of the Trinity wasn’t explained in the New Testament. And if they don’t, then why is the Trinity dogma today?
The Trinity is a Christian mystery—something that can’t be explained by reason alone. A supernatural explanation is necessary. (This raises the question: If it doesn’t make sense, why accept it? But let’s set that aside.) Apologists often admit that they will just have to ask God about it when they get to heaven.
That humility is laudable, but how about some of that in other areas? If you don’t trust yourself to make sense of the Trinity, why imagine that you correctly understand God’s position on polygamy, slavery, and genocide when the Old Testament gives clear support for them? Why imagine that your evaluation of abortion and gay marriage is correct when the Bible doesn’t address these topics directly?
If only the Trinity were a frequent reminder for Christians to be humble in their claims, it would be valuable for everyone.
See also: “God Has Many Names, But Do We Need One More?”

It is too late in the day for men of sincerity
to pretend they believe in the Platonic mysticism
that three are one and one is three,
and yet, that the one is not three, and the three are not one.
— Thomas Jefferson (letter to John Adams, 1813)

(This is an update of a post that originally appeared 6/10/13.)
Image credit: Wikipedia
 

World famous apologist William Lane Craig picks up a machete and hacks a path through difficult theology in a recent lecture (“The Concept of God in Islam and Christianity”). He doesn’t waste time building bridges with our Muslim neighbors but instead highlights their threadbare theology while he commits collateral damage to Christianity.
Defense of the Trinity (but with defenders like that, who needs enemies?)
WLC begins by stating that Muslims have misinterpreted basic Christian teaching. Early Christians called Mary the “mother of God,” and Mohammed misinterpreted the Trinity as a king-consort-son arrangement. The Christian Trinity isn’t like this, and WLC says, “It is no wonder that [Mohammed] was revolted by such a ridiculous doctrine.”
I’m not sure that he was revolted, but let’s look instead at this being a “ridiculous doctrine.” I don’t see what’s ridiculous about it (except for the evidence-less supernatural part, which is admittedly pretty ridiculous). You could find lots of king-consort-son triads in other religions—Zeus, Leto, and their son Apollo from the Greek pantheon, for example. If any collection of gods could rule the cosmos, I don’t see why it couldn’t be a family Trinity.
And WLC should be careful with that “ridiculous doctrine” crack since he makes clear that he doesn’t even understand his own ridiculous doctrine. Here’s his approach to the Trinity.

[The Trinity] is the doctrine that God is tri-personal. It is not the self-contradictory assertion that three gods are somehow one God. Or that three persons are somehow one person. That is just illogical nonsense.

That is indeed illogical nonsense. Unfortunately, it’s also Christian dogma. The fourth-century Athanasian Creed says in part, “The Father is God; the Son is God; and the Holy Ghost is God. And yet they are not three Gods; but one God.”
WLC could argue that the definition of the Trinity is not stated in the Bible. For evidence, he could point out that the early Church needed centuries to reach agreement on it (if it were obvious, it would’ve been dogma from the start). Unfortunately, this only undercuts his position further.
Craig continues:

Rather, [the Trinity] is the claim that the one entity we call God comprises three persons. That is no more illogical than saying that one geometrical figure which we call a triangle is comprised of three angles. Three angles in one figure. Three persons in one being.

Yes, a triangle is composed of three angles, but no, that is not a parallel to the Trinity. In fact, that commits the heresy called Partialism, the declaration that God is composed of three parts that make a whole. Other popular analogies that are also heretical for the same reason compare God to an egg (shell + white + yolk = egg) or to time (past + present + future = time).
WLC is in good company, and C. S. Lewis in Mere Christianity makes the same mistake: “In God’s dimension, so to speak, you find a being who is three Persons while remaining one Being, just as a cube is six squares while remaining one cube.” Six squares are parts of a cube, just like Father, Son, and Holy Spirit are parts of God? Be careful—a heresy like that can send a guy to Hell.
Modalism is another anti-Trinitarian heresy that modern Christians often fall into as they struggle to find an analogy by which to understand the fundamental concept of the Trinity. With this heresy, God can be analogized with water, which can be a solid, liquid, or gas. It declares that God can take on different modes, like an actor putting on different masks at different points in a play. (More on the Trinity here and here.)
WLC doubles down on his claim that Muslims (or anyone) pushing back against the Trinity is wrong.

Although this doctrine may seem strange to Muslims, once it is properly stated there is nothing illogical about it. It is a logically consistent doctrine, and therefore rationally unobjectionable.

Nothing illogical about it? You can’t even explain it without preaching heresy! The most honest explanation that I’ve heard is that it’s simply a mystery, and we fallible humans on this side of heaven won’t ever be able to understand it. The Catholic Encyclopedia explains it this way, for example. That doesn’t make the Trinity any more realistic, but at least Christians who say this acknowledge the difficulty.
God and love
WLC moves on to argue why the Christian concept of God is better than the Muslim version. The Trinitarian nature of the Christian god isn’t an embarrassment to Christians determined to argue that their god is monotheistic, WLC tells us; it’s actually an advantage.
Here’s his argument. First, “God is by definition the greatest conceivable being.” This is the beginning of the Ontological argument, where apologists imagine that they can think into existence anything they want, but let’s avoid digging into the problems with that argument and move on.
Point 2: “A perfect being must be a loving being, for love is a moral perfection.” Who says that love is a moral perfection? Is there a list of these perfections?
I agree that love is pretty great, but that’s because evolution has programmed me to think that love is pretty great. I feel this way for no more profound reason than that. Why imagine that the feelings we have for each other translate unchanged to God? Christians eager to excuse God’s genocidal demands suppose that we simply can’t understand his thinking. But then if we can’t understand his thinking, don’t pretend that we understand how he loves us or anything else or what “love” means at his level.
Anyway, “loving” is not on the short list of attributes that an objective observer would give the god of the Old Testament. Richard Dawkins’ famous quote at the end of this post summarizes some of these. The Bible makes clear that God is a lot more than just a cuddly teddy bear.

“Should you not fear me?” declares the Lord. “Should you not tremble in my presence?” (Jeremiah 5:22)

(More about God’s unpleasant characteristics here, here, and here.)
Point 3 in WLC’s argument: Love requires a target of that love, and for the current of love to flow before the creation of humanity, God couldn’t have been a single person. (And maybe because self-love puts hair on your palms?) Sorry, Muslims, your mono-monotheism isn’t as good as Christianity’s tri-monotheism.
Here’s how WLC puts it:

If God is perfectly loving by his very nature then he must be giving himself in love to another. But who is that other? It can’t be any created person since creation is a result of God’s free will, not a result of his nature. It belongs to God’s very essence to love, but it does not belong to his essence to create. God is necessarily loving, but he is not necessarily creating.

Wow—where did all these rules come from? It’s nice to imagine that God is loving, just like us, but how does WLC conclude that this is a binding attribute? And how can God not be necessarily creating since creating the universe must’ve been better than not doing so, and God always does the better thing?
And what kind of love are the three persons of the Trinity sharing? Is this romantic/erotic love? Parent/child love? And how do we know?
What would this love-in even look like? WLC apparently imagines that for the trillions of years God existed before the universe did, the three persons of the Trinity were just loving and loving each other. And then they’d start all over again. Was it nothing but compliments all day long?

“Y’know, those new trousers really work on you”
“Say, have you lost weight? You look great!”
“Oh, no—let me do that for you!”
“Can I get you a beer? You look like you could use one.”

WLC would probably say that we just don’t know and that it’s ridiculous to speculate. I like that—let’s just say we don’t know instead of this philosophical masturbation based on nothing.
Conclude with part 2. 

The God of the Old Testament
is arguably the most unpleasant character in all fiction:
jealous and proud of it;
a petty, unjust, unforgiving control-freak;
a vindictive, bloodthirsty ethnic cleanser;
a misogynistic, homophobic, racist, infanticidal,
genocidal, filicidal, pestilential, megalomaniacal,
sadomasochistic, capriciously malevolent bully.
— Richard Dawkins

Image credit: Luz Adriana Villa, flickr, CC

Let’s remember the key traits of the Trinity. According to the Athanasian Creed,

The Father unlimited; the Son unlimited; and the Holy Ghost unlimited. …
So likewise the Father is Almighty; the Son Almighty; and the Holy Ghost Almighty. And yet they are not three Almighties; but one Almighty. So the Father is God; the Son is God; and the Holy Ghost is God. …
And in this Trinity none is before, or after another; none is greater, or less than another. …

About Jesus, it says:

Perfect God; and perfect Man …
Who although he is God and Man; yet he is not two, but one Christ.

Okay, okay, I get it. Three persons, all equal. None greater than another. Jesus is unlimited, almighty, and perfect.
But does the Bible agree? Remember that, unlike the clear definition of monotheism in the Koran, the doctrine of the Trinity is not clear. It took almost four centuries to congeal.
Consider some Bible verses that challenge the Trinitarian concept as defined in the creed above. First, verses that portray Jesus as an ordinary person who didn’t know everything, who wasn’t 100% with the program, and who spoke to God as you or I would.

When Jesus heard this, he was amazed (Matt. 8:10)
[Jesus] turned around in the crowd and asked, “Who touched my clothes?” (Mark 5:30)
[Jesus prayed,] “My Father, if it is possible, may this cup be taken from me. Yet not as I will, but as you will.” (Matt. 26:39)
Jesus cried out in a loud voice, “My God, my God, why have you forsaken me?” (Mark 15:34)
Jesus often withdrew to lonely places and prayed. (Luke 5:16)
You are looking for a way to kill me, a man who has told you the truth that I heard from God. (John 8:40)
[Jesus said,] “I am ascending to my Father and your Father, to my God and your God.” (John 20:17)

Verses that state that only God has certain traits or abilities.

No one knows about that day or hour, not even the angels in heaven, nor the Son, but only the Father. (Matt. 24:36)
[Jesus said,] “The most important [commandment is:] The Lord our God, the Lord is one.” (Mark 12:29)
God, the blessed and only Ruler, the King of kings and Lord of lords, who alone is immortal and who lives in unapproachable light (1 Tim. 6:15–16)

Verses that portray Jesus as inferior to God.

“Why do you ask me about what is good?” Jesus replied. “There is only One who is good.” (Matt. 19:17)
[Jesus said,] “the Father is greater than I” (John 14:28)
The head of every man is Christ, and the head of the woman is man, and the head of Christ is God. (1 Cor. 11:3)
The Son himself will be made subject to him who put everything under him, so that God may be all in all (1 Cor. 15:28)
You have been raised with Christ, set your hearts on things above, where Christ is, seated at the right hand of God. (Col. 3:1, see also 1 Peter 3:22)
There is one God and one mediator between God and mankind, the man Christ Jesus (1 Tim. 2:5)

Ever-nimble Christian apologists have had 2000 years to find responses to many of these. Perhaps they’ll argue that we’re seeing the limited Man side of Jesus here, not the God side. Or that other verses can be brought in to bolster the Christian position. Nevertheless, the simplest explanation is that the Bible is a collection of books from authors (many unknown) who had similar but not identical religious beliefs, which has been modified in unknown ways over the centuries, and which has no more accuracy in its depiction of the supernatural than the Iliad.
See also: “The Long, Strange Story of the Trinity.”

It ain’t supposed to make sense; it’s faith.
Faith is something that you believe
that nobody in his right mind would believe.
— Archie Bunker

Photo credit: Samuel Livingston

Can’t Christianity think of a better name for its god than “God”? While modern Jewish authors sometimes refer to him as “G-d” so that they don’t violate the fourth commandment, there is no such fear of blasphemy among Christians. A god named “God” is like a cat named “Cat.”
The fourth name of God
While we’re talking about names, if Father, Son, and Holy Spirit are the persons, what do you call the union of these into one god? Ice, water, and steam are three states of H₂O. Shell, white, and yolk form an egg. Father, Son, and Holy Spirit form who?
You need a fourth name. Do you call it “God”? But the Bible tells us that “God” is the one who created everything, and that’s supposed to be the Father. The Father can’t be both the first person of the Trinity and the overall god at the same time.
Calling this union the Trinity commits the heresy of Partialism, the claim that the three persons of God are three separate parts. Father, Son, and Holy Spirit don’t form a what, they must form a single, unified who. Another problem with “the Trinity” is that’s an odd name for a monotheistic god. It’s a label, not a name. Call the three persons “a council of three” if you want, but that doesn’t make clear the unity like a proper name would.
That the Old Testament uses one name for God (okay, it uses lots of names—Yahweh, Jehovah, Elohim—but that’s a different issue) makes clear that they saw no distinction between God the Father and this Trinity. Without this distinction, it’s clear that there is no Trinity in the Old Testament.
Let’s see this another way. Consider this passage from Isaiah 45:5–6:

I will gird you, though you have not known Me; that men may know from the rising to the setting of the sun that there is no one besides Me. I am Jehovah, and there is no other.

There are two interpretations of this passage.

• If Jehovah is a synonym for “the Father,” this means that he reigns alone (since “there is no other”) and we must discard the Trinity.
• If Jehovah is a synonym for “the Trinity,” then it makes nonsense of the singular pronouns (Me and I) in these verses and confuses passages such as “Then Jehovah spoke to Moses” (Ex. 40:1) or “After Jehovah had spoken these things to Job” (Job 42:7).

The problem, of course, is demanding a Christian interpretation of a Jewish text. There’s nothing confusing here from a Jewish viewpoint, which was the intended audience. There is no Trinity, and the only god that exists is Jehovah.
Well, at least the only god at this time in the evolution of Judaism. It’s a little more complicated because Old Testament Jews didn’t begin as monotheists. The Old Testament documents their evolution from a kind of polytheism (that’s an aside that I explore more here).
Admittedly, one handy trait of the Trinity is that it gives Christians a way to salvage some embarrassing passages from the Old Testament.

Let us make mankind in our image (Gen. 1:26)
The man has now become like one of us, knowing good and evil (Gen. 3:22)
Let us go down [to Babel] and confuse their language so they will not understand each other (Gen. 11:7)

These are no problem if “us” refers to the three persons of the Trinity. But if God were a trinity, it’s hard to imagine him not making this clear from the beginning. Judaism’s evolution from polytheism explains this nicely. The concept of the Trinity confuses, it doesn’t clarify.
See also “The Long, Strange Story of the Trinity.”

Ridicule is the only weapon which can be used
against unintelligible propositions.
— Thomas Jefferson

(Some of this post was originally published 11/11/11.)