You’re saying that god is so oblivious (even though he’s supposed to be omniscient) that he’ll be fooled by you claiming to believe just because you’re hedging your bets?
More that repetition reinforces an idea. By commiting to the bit and accepting a God at face value, you reduce your psychological defenses when the priest or prophet comes around with the next ask.
So you admit you believe in God? Then you won't mind putting a few coins in the collection plate to prove it.
Oh, you've already donated? Surely you'd be comfortable making a confession.
My son, you've got so many sins! Surely you'd like to join our prayer group to get yourself right with the God we all agree exists.
Can't have prayer without works! Time to do some penance.