The Pope, never one not to choose his words carefully, says this:
‘While repeating a firm deploration for any form of violence, His Holiness hopes that the blood that has been shed by such a faithful disciple of the Gospel can sow hope for the building of real fraternity among people with recriprocal respect of everyone’s religious convictions.’
Note that he doesn’t say religious beliefs, which would be another thing entirely.
That is, if you hold a certain conviction, you are in a state of having been convinced by something. If you’re in such a state, then it’s only polite to respect that. So if you are convinced that the moon is made of blue cheese, so much so that you’ve invested all your money in a blue-cheese moon mining company, we should respect this fact and be sensitive towards it. It simply wouldn’t do to fall about on the floor laughing uncontrollably at your excitement at the prospect of the immense riches you might accrue.
However, your belief that the moon is made of blue cheese is clearly ludicrous, as is your belief that for one brief moment every Sunday you engage in cannibalism, and neither demands any respect whatsoever.