Would it be wise to tell him?

I have feelings for my best friend of two years and am not sure if I should tell him or not. He is LDS (Mormon) and I am not, so I'm not sure if we'd even be able to make anything of it. However, he's getting ready to move into my family's spare apartment above our garage for his last two years of college and I'm starting to get a bit antsy with him being at such a close proximity, not to mention that he's actively dating and looking for a girl to marry. Would it be wise to tell him what's on my mind, or should I keep it to myself? Is being honest with him worth risking the casual comfort we have right now? I don't know if he feels the same about me or if religion would be enough to make it all null, but part of me says I'd regret keeping quiet down the road.