The usefulness of Christian belief
Christians might come at this from the other side: “Don’t you at least admit that it would be nice if there were a God?”
Not if it’s the monster described in the Old Testament.
“But the atheist worldview is so depressing! You imagine that we’re all alone. And what happens after you die?”
What happens to a pet when it dies? If animals just die, with no afterlife involved, why should it be different for humans (except that it would please you to be otherwise)? Let’s be adults and follow the facts—there simply is no good evidence for an afterlife, so we shouldn’t organize our lives as if there were one.
As for the atheist worldview being depressing, some parts are, as Julian Baggini correctly points out. But we try to act as adults and accept the evidence. There are no fairies or unicorns or wish-granting genies, darn it. If you had cancer, wouldn’t you want the unpleasant truth so you could take action?
Imagining away the bad parts of life without evidence is something atheists won’t do, and our lives are as fulfilled as Christians’ are. We take pleasure in a child’s laugh or a beautiful sunset just like anyone else. Because we accept that this life is all we have reasonable evidence for, we know that every day is precious. If instead you imagine that you’re en route to heaven, and life on earth is just a brief and insignificant stopover, you may treat life differently.
It wouldn’t matter if the atheist worldview were bleak—as adults, we embrace reality and follow the evidence. And why imagine that the atheist worldview is the bleak one? The Christian must imagine that God is constantly monitoring them to make sure that believe and do the right things, and if they don’t thread this needle, they’re headed for Hell. They must imagine that God is there with them in terrible hardship, except that there’s never any evidence of this (and the hardship was imposed by God). Some Christians must admit that God never answers their prayers, though the Bible claims he answers everyone’s. This view of God wouldn’t be any bleaker if God didn’t exist.
Maybe that’s why the most religious states also consume the most antidepressants.
The Christianity-is-pleasing view seems to be losing its power. The remarkable rise in the U.S. in the “Nones” (those unaffiliated with any religion), from 6% in 1991 to 25% today, comes from a rejection of Christianity’s intellectual standing. The leading reason by far for rejecting their childhood religion is that they simply “stopped believing in the religion’s teachings.”
Related posts:

• “A Distillation of Crazy”
• “Is Life Absurd Without God? A Reply to WLC’s Influential Article.”
• “Christianity’s Bogus Claims to Answer Life’s Big Questions”

Other posts responding to atheists:

• “Does This Atheist Have a Point? Or Is This a Sycophantic Poe?”
• “Does Secularism Have a Debt to Christianity?”

We must love the universe,
but the universe doesn’t love us back.
— Unknown

We’re either alone in the universe or we’re not.
Either way, the thought is staggering.
— Arthur C. Clarke (paraphrased)

Image credit: Tobias Wrzal, flickr, CC