Many people have a list of criteria for the people they are willing to date seriously--whether it is conscious or not. Some things on the list may be "it-would-be-nice-ifs" and others are definite "must-haves." Most likely, the guy you're dating prioritizes religious compatibility more than you do because religion is more important to him.

You can try to get to know each other better and maybe he will come around, but it sounds as though he may have already decided that there is no potential for a romantic relationship. Since you like hanging around with him, you might want to consider remaining friends and letting go of your romantic aspirations...if that's at all possible.

Take care.