... Any proof that that was the reason?...
You mean was I inside his head when he made that decision to become religious? No, I wasn't.
But you know what psychologists say about recognizing a liar? They tend to add unnecessary detail. So, let's see:
"I am a Christian,..."
So far, so good. I could actually almost believe it. But he doesn't stop while he is ahead, he has to add details:
...and I am a devout Christian...
Seriously, "devout"!? Someone who was raised in several generations of non-religious people on both side of the family, is now a "devout" believer!?
Then, as most liars, he has to continue to add unnecessary details:
...I believe in the redemptive death and resurrection of Jesus Christ. I believe that faith gives me a path to be cleansed of sin and have eternal life.
A young, highly educated person, professor, raised in a non-believer family, now believes in fairy tales!? Resurrection, redemptive death, eternal life!? Seriously?