An atheist would argue: If god does not exist, why is religion a multi billion dollar industry? The answer is: because there are people who believe in its effectiveness and put their money where their mouth is.
The people need to be presented something to believe in before they can pay money for it or else they wouldn’t know it existed and therefore wouldn’t be able to put their money where their mouth is. Getting the word out is the most important thing. missionary work and preaching the gospel is a main tenant of Christian theology for example... because they understand advertising and marketing is important. This is why the Catholic Church covered up the molestations of children, because they understood bad PR would hurt their bottom line.