Just in case you didn't know:

article: https://everything2.com/title/The+Heinlein+-+Hubbard+Wager+Myth

relevant bit:

"RAH and LRH had one or more discussions during 1944 and or 1945 when they were both in Philadelphia, and RAH pointed out to LRH that religions had an inordinate amount of legal latitude in the U.S. and that churches could engage in a great many activities otherwise thought of as secular, under the tax and other protection churches enjoy. He had already explored these ideas in some of his stories and was to revisit these notions in their original form in Stranger. It is possible that this conversation or series of conversations took place as late as December 1945 or early 1946 and in Los Angeles."

The theme of money and religion was apparently a very popular one for Hubbard as he seems to have mentioned it at several other informal discussions around the same time. In a 1978 interview Harlan Ellison commented "Scientology is bullshit! Man, I was there the night L. Ron Hubbard invented it, for Christ Sakes!...We were sitting around one night... who else was there? Alfred Bester, and Cyril Kornbluth, and Lester Del Rey, and Ron Hubbard, who was making a penny a word, and had been for years. And he said "This bullshit's got to stop!" He says, "I gotta get money." He says, "I want to get rich"."

... which is also the origin of the word "grok".

Full circle!