[header] How to respond when a gay friend comes out of the closet [title] Be civil regardless of your beliefs. [step] Not everyone shares the same beliefs and it's possible that you may have reservations about homosexuality. While you have every right to maintain any set of beliefs you wish, don't hold your friend to the standard of your belief system. 
[substeps] Even if you don't understand, try to appreciate the fear and stress involved in coming out to you. Your friend is still your friend, regardless of your feelings about homosexuality.