Many may actually believe in [deity] so they are on a righteous path, while still many more don't truly believe (or live according to [deity doctrine]), but they see the sheer amount of wealth and prestige that these systems offer. So they play along.

And then some of those players do a miracle, or give particular effective sermon at the right time, and they're sainted. Soon believing themselves to be prophets and indeed propped up by the hard work and resources of others.

At least the deities of yore had cool characters.

    > "most of which was borrowed"

Ethically, many of the organisations investing in this subscribe to the "Greater Fool" theory, so I'm not going to be overly sympathetic to their plight if it goes south.