AITA for joining a college Bible study as an atheist?

So, I’m a freshman in an engineering college in the US, and it’s a pretty small school, so the community here is tight-knit. I have this friend, J, who is a devout Christian. He’s a good person, though a bit annoying at times, and we get along well. One day, I asked him if I could join the Bible study group he’s been attending, and he agreed to bring me along.

I’m an atheist, but I don’t think not believing in God or Christianity means I should ignore the topic entirely. I enjoy reading literature like Paradise Lost and learning about various religious and philosophical ideas, so I thought, "Why not give it a shot?" I went to my first Bible study meeting and thought it would be a good way to explore things a bit more. So far, I’ve only been to two meetings, but they’ve been... interesting, to say the least.

First of all, this Bible study group is pretty unfocused. We once had a half-hour debate about the meaning of fish volleyball (don’t ask, I have no idea). I’m guilty of contributing to this chaos because I tend to crack jokes when everyone’s silent or debating. I’m not being insensitive—I just try to lighten the mood a bit.

This group is also the type that goes out to dinner together before their meetings, but I don’t participate because of my schedule. After the first meeting, one of the members texted me asking if I was taking the Bible study seriously, and whether I would be willing to go to church with them. I declined the church invitation because, honestly, it’s a big time commitment, and I’m not comfortable with it.

I tried to avoid the tough questions and keep things light, but it didn’t work. When I went to the second meeting, I decided to keep quiet and just observe. That backfired. The group leader found out I was an atheist—J and I had some late-night conversations about our worldviews—and things went downhill from there. I stayed silent for most of the meeting, but that didn’t help either. The group ended up getting into a heated discussion, and I basically became the punching bag for the next hour.

They accused me of "making a mockery of their group" and speculated that I was there just for a laugh. I tried explaining that wasn’t the case, but they wouldn’t listen.

Later, J talked to me, and apparently, they were asking him if I would be willing to leave the group because “I was causing problems.” I decided to stay and keep learning, but now I’m wondering if I’m in the wrong here. AITA for joining a Bible study group as an atheist?