Is it possible to maintain friendship with church people if you suddenly stop attending said church?

Not if it was just an acquaintance because you met in church no.

If you don't already know, you'll figure out real quick which of the "church people" are really friends.

It's been about 15 years since I left Christianity. My contact list on my phone has 3 or 4 people I knew from church. In the first few years after I left there was another handful who would occasionally call or drop by.

Not long at all! It's like if you leave a church and join another it is seen as betrayal. Shouldnt be like that. We all belong to the body of Christ and we should be one in Christ no matter Which church you belong to.

There are people my sisters met in church who are still friends even after that church split up, and everyone went their separate ways. It’s been about 17 years.

No, in my experiences in the past they shun you and then spread hateful gossip about you. I will not participate in organized religion.

The church i was in actively shuns the non-active members.

I cant be friends with people that are religious enough to go to church, mosque, etc..

They're all on a moral high ground and think they have life figured out because they choose to not be a critical thinker. In my opinion they're all extremely emotional thinkers. Generally low iq too (not all).

If a person was only friends due to having the same religious beliefs then they weren't friends to begin with.

They'll shun you faster than you can blink your eyes the moment they realize you left.