Because religion is laughable

Hobby Lobby Christian Chastity Belt

Funny Hobby Lobby Christian Chastity Belt Joke Picture
Funny Hobby Lobby Christian Chastity Belt Joke Picture
Genuine, lace-trimmed.  For your one and only. Got a female employee? Keep her under lock and key with the best Christian birth control ever.
Christianity and sexuality have always been uncomfortable bedfellows, if you'll forgive the pun.  Islam at least, for all its foibles, got that bit right, what with the promise of plentiful virgins to its enthusiastic martyrs.

Of course, the story for women is not quite so perfect.  Religion and misogyny seem to go hand in glove, which is what you'd expect if religion were invented by men.