It does not matter what church the guy belongs to. He is a crook, cheat, etc. Whatever you want to call him. He definitely is not practicing his religion. Attending church service on Sunday has nothing to do with practicing one’s religion. It is what one does outside of church.
You lost your job for not acting wisely. You knew what he was like, yet you acted in a passive agressive manner towards him. That was your mistake. Wise up.
Forget going to his church. You could get into a difficult legal situation. He has the bucks, you do not, and his pastor and other high rollers will protect him. You could end up in jail for trespassing.
He fired you and not for cause. I presume your state has unemployment insurance. So, file for it immediately as there usually is a waiting period.
Go to the INS or some other Federal agency and turn him in for employing illegals, and it sounds like lots of them. Be specific as to numbers. This guy is just a dumb prick. He is so full of himself, he thinks he can push people around. Well, he has lots to hide, so that was quite dumb on his part. Good luck.
Good advice.