I am with SO. I assume it is a Texas thing. Not as prevalent here near Houston. I guess because there more than two religions (Catholic and Christian.)

Yes, definitely. However, I do find it mildly entertaining with the look on their face when told differently.

This happens to me so much here in Texas. At first I don't tell people I'm an atheist I'll just sit and talk with them and we'll have a normal conversation like two normal people and then they get to like me for me. Next thing I know it's hey what church do you go to or hey would you like to go to church with me this Sunday? When I tell them I'm an atheist all of a sudden it's like how can you be an atheist? You seem so nice. As if atheist or the meanest group of people in the world. The other day I was at the laundromat talking to a woman and she found out I was an atheist so she had a million questions and I answered most of them but at the end she says I know that you would be a great Christian. I told her I was a Christian up until I was 25 years old and she said see I know that's God working through you. No matter how much I tried to convince her that I am an atheist and I will always be an atheist and I am happy being an atheist she was convinced that I had to believe in God and even started crying because she was afraid I was going to go to hell. She then told me she would go home and fast for 3 days for me. I asked her not to punish herself for me much less for herself. I've not seen her since.

I think it's pretty common for some people to just assume (without ever realizing or even thinking about it) that everyone goes to church. It happens when people are never exposed to other ways of being.

Then you have those who feel (again, probably without much examination) that the only right way to be is to belong to their preferred in-group--so anyone who seems "right" (i.e. not a degenerate) must belong to said in-group.

I've seen this so much in good-hearted people that I don't really fault them for it. You don't know what you don't know.

Once you know and you still chose to save yourself some mental effort by relying on flawed heuristics instead of permitting everyone's humanity to enter your eyes, that's a sin.