I know it’s not the best advice, but I really recommend trying to visit. If you can’t, spend a week checking Oberlin’s yik yak. Obviously it’s an anonymous platform so it will differ slightly from what you would hear on campus but it’s a pretty good representation I think.
No one can know if the transition will be too much for you, except you. Saying you are conservative and christian describes most of the country to it is hard to know if you will be comfortable. You have obviously done research on Oberlin and know it’s a very, very liberal school, so I think it’s just up to how you feel about that. Do you want to be surrounded by people more similar to yourself or do you want to maybe be the odd one out? This election is crazy and if you say you’re a Trump supporter on campus you may get shunned, but I don’t think supporting being generally more conservative will lose you any friends.
Most people don’t seem to care about religion from my experience. The most outwardly practiced religion was Judaism, from my limited experience of religion on campus. Many students I’ve met were spirtual on some level, just not involving organized religion.
There is a bit of an Oberlin bubble collective mindset where a few loud minority opinions get assumed to be the default for everyone and, for any number of reasons, no one wants to rock the boat. I’m guessing you will not agree with most of these opinions, and I know I definitely didn’t when I was there, but it’s still a cool experience to be surrounded by tons of opinions you think are crazy but in the end make you a better person.