I would expect a reply along the lines of: It's precisely because I can't trust my own reasoning when deciding which false beliefs I should have that I accept these which are handed down. I pick Judaism because it's the oldest and thus has shown through memetic competition that it's the strongest set of false beliefs one could have.

Or ..." I pick Christianity because it's the most popular and has therefore proven itself memetically competitive."

I have a lot of friends who think "it's old therefore it must be good to have survived this long" about Tarot and eastern religions etc.

Personally I'd wanna eliminate the false beliefs even if it cost me my mojo, but that's a different set of priorities I guess.