Would this be awkward, especially bc he knows why?

There is this guy who likes me, but the thing is, I don't feel the same way. We go to Catholic school, but the thing is, he is a really REALLY evangelical Baptist. idk why he goes to Catholic school, but there u go. He and I argue about religio, and politics, and everything under the sun. but for some reason he likes me. He know I wouldn't date him, and, sad to say, religion is one of the reasons why. It's just, guys who try to convert me at lunch really aren't my type. So how do I let him down easy without bringing religion into it?