“Holy crap”, “God damnit”, 'Dear god", “What the hell”, these are all things I say regularly despite not believing in any holy things, gods, or hells. It’s simply a part of my vocabulary, which tends to happen when you grow up in a country surrounded by people that actually do believe in those things.

Different cultures I guess? It’s pretty common to hear around me regardless of religious belief. In fact I’d think the religious would be less likely to use it in such a way?

I think it’s just part of how languages work and people communicate, at least for people learning a second language - but I even do it in my native tongue, so I think it’s general.

For example, if when you are learning English you hear a lot of people say “God dammit” when they are frustrated, then when you are frustrated you’ll probably also start saying the same without ever even thinking about God. It’s essentially just a series of sounds when you learned to make to express frustration.