Here is the Kalam Cosmological Argument (KCA):

1: Whatever begins to exist had a cause
2: The universe began to exist
3: Therefore, the universe had a cause

This post is #2 in a three-part series responding to a Christian defense of the KCA. Part 1 here.
Below, the skeptical argument is shown in bold and the Christian response in italics.
“5. The first cause is logically incoherent because it existed ‘before’ time.” This isn’t an objection to either premise.
This is indeed an objection to premise 1. It questions whether there can be a cause of any sort given that time didn’t exist before the universe did.
The First Cause didn’t precede the universe, because it acted in the first moment—that is, the First Cause and the first moment were simultaneous. “So what we have is a timeless, unchanging (because it is timeless) First Cause whose first act is bringing the world into existence.”
This is metaphysical bullshit. The simple solution is to drop the idea of any cause (First or otherwise) for the universe. The God hypothesis is jammed in as the answer despite its not fitting into this puzzle at all. The naturalistic explanation doesn’t need one, and the KCA vanishes without one.
How could a god outside of time decide anything, such as that the universe should be created? “Timeless and unchanging” means frozen and inert. No conclusions, no changing of his mind, no initiation of any creative act.
“What could cause the universe if there were no time beforehand?” is like “How could a frozen and inert god do anything, like create a universe?” And they’re both neatly dismissed by hypothesizing no cause for the universe, as allowed by quantum mechanics. God becomes a solution looking for a problem. Apologists spend more effort keeping the God card relevant than using it to show that it explains things better than naturalistic solutions.
Cosmologist Sean M. Carroll debated Craig on cosmology (more on that debate here), and Carroll ticked off several models of the universe with no place for a First Cause such as a universe with a beginning but no cause and one that is eternal without a beginning.
And let me step back to marvel that this godly First Cause is advanced by apologists with no evidence whatsoever. Carroll noted that cosmology textbooks don’t appeal to “transcendent cause” or “First Cause” or God, they use differential equations!
“6. If some metaphysical truth is not well-established, one is unjustified in saying it is true.” Does “not well established” mean that philosophical truth is discovered by a poll? And now can new truth bubble to the surface if no one accepts it until a majority do?
When metaphysicians have a track record like scientists, where they give us reliable new knowledge, then yes, polls would be useful. We laypeople could rely on them to know where they’ve reached a solid consensus, and we could treat that as provisional truth. But metaphysics has no such track record. (I argue that laypeople must accept the scientific consensus here.)
As for his concern about “a new idea is fine as long as it’s not new,” we must separate the experts from laypeople. In an evidence-guided meritocracy with a high bar for entry like science, the experts can dream up, advocate, and accept whatever they feel the evidence demands. While we lay outsiders can critique, we have no standing for accepting anything but the consensus (where it exists).
That describes science, not philosophy or metaphysics.
“7. There could be other deities besides the Christian God.” This doesn’t object to either premise of the KCA. Let’s be clear that the KCA is used as natural theology (understanding God through nature), never revealed theology (understanding God from his personal revelations).
Nevertheless, the properties of the cause of the universe—timeless, spaceless, changeless, powerful, creator—do sound like the Christian god.
“Imagine, if you will, a timeless, spaceless, all-powerful Creator of the universe. Sounds like God, doesn’t it?” Well, it sounds like what Christians today think of God, but consider God before he hit the big time—back in the Old Testament when he was still doing vaudeville. He had to personally investigate Sodom and Gomorrah to see if the gossip he’d heard was correct (Genesis 18:21), he regretted having made mankind (Gen. 6:6), he spoke to Moses “face to face, as one speaks to a friend” (Exodus 33:11), he was beaten by the Moabite god Chemosh and couldn’t defeat tribes with iron chariots (more), and he was just one of many gods in a pantheon.
He was more super than the rest of us, but certainly not the omni-everything god of today. God has evolved.
Concluded in part 3.

Astronomer Pierre-Simon Laplace presented his
5-volume work on the solar system to Napoleon.
Napoleon wanted to know why it contained no mention of the Creator.
 Laplace replied, “I had no need of that hypothesis.”

Image credit: NASA