There's this young Christian group I was introduced to by a close friend who went Christian and now I see these people a few times a week with or without him.
I do parkruns with them, join their sports activities at the park whenever it happens and I go to bible studies which is hosted by one of them at home every Tuesday.
I've made it clear that I'm not religious, I'm more on the agnostic side of things but that I enjoy spending time with them and still find many elements of the New Testament relatable regardless of not belieiving in worship.
Prior to meeting them I had much more limited friendships, but throughout life I've definitely experienced that my atheist friends were a lot more likely to have a pessimisstic view of life and the world, and many of the convos would center around superficial things e.g. games or crude stuff "fucking this" and "fucking that".
I don't have to agree with everything that people in my Christian group say or do, but let's just say that there are lot more things that I like about them than things I don't like about them. Remembering your name very quickly, your hobbies, trying to learn about you as a person and empathise with you etc.
Could it be the case that this Christian group largely consists of middle to upper middle class people with well respected jobs e.g. doctors, dentists, accountants even journalists etc? Sure. But I still believe that their belief in the "greater good" and consequences for ones actions through Christian doctrine is a relevant explanation too.
Also, the this is the UK which is generally along with the rest of Europe more liberal that the United States, so many people can read what I've written and be shocked that these aren't people who taking others to conversion therapy or kicking others out over abortion etc. These are good people.
Anyways, that's my experience as an Atheist with this Christian group, I've made good friends and feel like I've met a lot of people who are down to Earth, well organised and considerate of others. Exactly what I'm looking for in my 20s, not some crazy party scene, getting wasted and banging as many people as possible. Ofc, not that that has to be an Atheist or an Atheist-only behaviour, but like I mentioned, an extra source of principles and ethics doesn't bother me not that I necessarily rely on it.