◆ Welp, then he is not your friend at all... True friends accept each other no matter what.
In my case, if they're my friends, I just try to tell them it's okay because it's their opinion but we have to accept each other no matter what we like or dislike, our preferences and personal likings, and of course, that if they will not accept me, tell them to please stop talking with me if they please. I do respect their opinions about me though, because I like to respect everyone, and in the end nobody thinks in the same way, may they be my friends, enemies or neither. That way, sometimes, things can be worked out
But not even that helps sometimes, that's when the other person just... Is not a good friend at all
As Fluffles said, in this case, many people overreact about their religions to the extent they don't even understand it well.
I had been discriminated for the same thing (not religion involved, though) even when I don't say I'm a furry myself, but I just let people decide if I am or not! People blinded by ignorance shall always exist, sadly.