Keith DeRose, philospher at Yale and running partner of Miroslav Volf, has a long and thoughtful post on “Delusions of Knowledge” that lead to a loss of faith. Worth the read, if you have the time — and don’t miss the comments. Here’s a taste:
However, over the years, I’ve had the opportunity to talk with some people who did get to the point–often for years, during adulthood–of acting and talking as if they knew that God existed, but who later “gave up the faith,” as it’s often put (often by their disappointed relatives and/or former colleagues in the faith), becoming atheists or self-described agnostics. They of course didn’t take themselves to know that God existed at the post-crash time that I talked with them, but what I found most interesting was asking them what they now thought of their past selves. Did their past selves sincerely take themselves to know that God existed?
This tends to get complicated quickly. Though there are important differences among people I’ve talked to, they usually thought that there was some element of insincerity, lack of genuineness, or even phoniness, in the certainty they had earlier projected to the world. But it generally doesn’t seem to have been cases of straightforward deceiving of others: they often think that they themselves had been deceived about what was going on. That their earlier selves had been under a delusion of knowledge about God’s existence fits in quite well with the picture that many of these people have of their earlier, confident-sounding selves.
Often, their becoming atheists or agnostics was a process of becoming aware of the possibility (though some seem to think that deep down they always had this worry, in which cases the process seems to have begun by coming to face a possibility they had always been dimly aware of) that the certainty they seemed to feel was not an honest or genuine response to what experience of God they might have had, but was largely motivated by the desire for their experience of God to be genuine and/or was driven by social forces involving identifying with the believers (or at least folks they took to be believers) around them, and then that suspicion growing to the point that they felt the honest response was just to admit that they don’t, and never did, have any genuine knowledge of God’s existence.