Peter Hitchens, in his book The Rage Against God, tells us what he thought he knew about the Christian faith before he believed it:
I was convinced that a grown-up person had no need of Santa Claus fantasies or pies in the sky. I knew all the standard arguments (who does not?) about how Christianity had stolen its myths and feast days from pagan faiths, and was another in a long line of fairy stories about gods who die and rise again. Since all the great faiths disagreed, they couldn’t all be right. Jesus was curiously similar to Mithras, or was it Horus? Etcetera, etcetera, etcetera, easy as pie, not in the sky, and made still more facile by the way such youthful epiphanies are applauded by many teachers and other influential adults, and endorsed by the general culture of my country, which views God as a nuisance and religion as an embarrassment or worse.