Hearing new voices with perspectives shaped by new places and ideas strengthens us. That is the underlying principle of freedom of speech and freedom of the press in liberal democracies.
You argue for weakness: weakness of mind, weakness of spirit, and weakness of morals.
The reason behind priests not being allowed to marry originally had nothing to do with their faith though. It’s because Catholic priests were bequeathing church assets to their children when they died. The church just put a thin veneer of dogma on top of the reasoning when they used the dictate of no marriage to stop the theft.