Two things worth saying:
I believe Gervais is being genuine. He grew up in the church like many atheists do, and he had an experience in his late teenage years where his mother, who was a big influence in his religious life, and tried to shut up his brother who apparently had the truth about God. What's the secret?
God doesn't exist. God is a babysitter, or more specifically the Son of God is the babysitter and his mother used Jesus to keep him out of trouble.
I don't know Gervais' mother, but going by his account I'm not surprised Gervais lost his faith. It was based on deception and use misuse of God for practical reasons. This isn't an unpopular view. Many people who are atheists or at best nominal Christians want their children involved in church life because it's good for them. I agree it is good for them. But if what's taught is morality alone, then it will fall flat like in Gervais' case. For him, it took one interaction between his brother and his mother, then an hour of thinking and it's done.
Who's the god Gervais believed in?
That god wants everyone to do good, and if they don't do good, they will be punished. Santa Claus is similar. This is second grade Sunday school theology and if a person keeps it the rest of their life, their faith will disintegrate as fast as his did. Of course, God is concerned about what we do, but why and to what end? That's the real question and it's never asked.
God is all about morals, and the Bible is solely a book on morality with poor history and science thrown in for fun. I'm not surprised Gervais rejected that god. You can hear his view of God come out in his description of Jesus.
"Jesus was kind." That's beautiful. Just a really nice guy.
And what about the Fall?
God made two mistakes: letting the serpent loose in the garden and making him an atheist. God didn't do either of those. Free will left the option for the serpent to deceive and for us to be deceived, and Gervais chose to be an atheist in his hour of thinking over what his brother said.
What he's showing is a somewhat sophisticated view of the Fall (evil in the world, natural disasters, the serpent in the garden, etc.) and a very poor view of God's plan to redeem us. Really? Do you honestly think after all the evil and corruption in the world God's only solution was to send another human to tell us to be nice?
The problem is that he wasn't taught the doctrine of the Incarnation, the Atonement, the Resurrection, etc. God didn't merely choose to teach us, he chose to come down Himself and redeem us all the way through. Our wills have been corrupted and we have to be refashioned, and we're done so to be greater than we were before the Fall. But he doesn't say this, does he? Probably because he wasn't taught it.
If he was given an apology for the way of salvation, I bet he'd say it was absurd. It is. I agree. The truth of it is probably the hardest to accept, something he alludes to at the beginning of the video.
But isn't it interesting how quickly he moved from his theism to his atheism? A lifetime of teaching and religious life gone in an hour, and no one objects. His family doesn't stop him either, other than his mom's scolding his brother.
What's deceiving about his story is that he says he grew up believing in God and in a Christian home. This is not true. If his mom never believed it, then it's no surprise his faith is paper-thin. This is the problem with religion as morals alone.