Celibacy is always, shall we say, an affront to what man normally thinks. It is something that can only be done, and is only credible, if there is a God and if celibacy is my doorway into the Kingdom of God. In this sense , celibacy is a special kind of sign. The scandal that it provokes consists precisely in the fact that there are people who believe these things.
--Pope Benedict XVI, Light of the World, 2010