I know this isn't exactly appropriate for this site--I'm not a parent, I'm a son--but I think it's still applicable to the community here. I would prefer feedback from actual parents concerned about other parents, not people who theorize about child-parent relationships, but if there's a better q/a site for me to migrate this question to, please let me know.
I am 20 years old, third year in college. I went to church about every sunday for the first 18 years of my life, with my parents. When I moved out to go to college, I stopped going to church all together. My mom still tells me every time I see her (whenever I go home, about twice a semester) that she's praying for me. I go with my parents to church every time I'm home, sing the songs, pray the prayers at dinner, the whole deal. Both my parents ask me if I've found a church yet, how often I go looking, etc. but I always manage to give them the excuse that I've been really busy with school (which is true, but of course irrelevant).
The truth is, I haven't self-identified as a christian since I was 16. I've avoided telling my parents this because... well, it would be very difficult. My mom would probably get really upset and my dad would probably just try to get in a huge theological argument with me, but it wouldn't change my mind, it would distress them further, and lead to a large divide between us. At the same time, it feels wrong to outright deceive them all the time. I'm definitely willing to continue whatever traditional religious stuff I would otherwise do to please them, even though it all means nothing (other than family tradition) to me.
As a parent, can you give me some advice on what to do? Should I have the talk and break it to them? If so, what's the best way to do that? How can I avoid religion causing a divide between us?