Should I state my religion on college applications?
Great question! Typically, college applications are only for relevant information about you at a candidate for that university. So, if your religion is relevant to the university, meaning the university is a denominational institution (e.g. they are a Catholic University such as Villanova University) then I would include it. Additionally, if your religion is an important part of who you are as a student and person, then include it, maybe in one of the written responses.
Overall, I don't think adding it will negatively impact your candidacy for a university but only add it if it means something to you.
It's a choice that is entirely up to you especially in the case where the school is not requesting for it to be included or stated in your application. However, if you are applying to an institution whose requirement is for their students to be affiliated to or with a religion then it might be helpful to include that as it speaks to the fact that you are willing and able to abide by certain set rules and regulations, you won't flout them and you're comfortable to a relatable & certain extent whatever consequences exist for when any student does.
Most of all before selecting or applying to any college ensure that you do an extensive research to see if their style, mandate and policies align with your belief and person.
All the best and God bless you!