Do you think its wrong to mock religion?

One can believe whatever they want but when they start stating those beliefs are facts, I interject whatever I feel is appropriate.

I once told a Jehovah Witness co-worker that I would not tell her how stupid her beliefs were if she would stop telling me how stupid my beliefs were.  When she said, "I never said your beliefs were stupid", I countered with, "You obviously think my beliefs are stupid because you're proselytizing."  We worked together without any religious comments for the next 18 months.