[BluffTHIS!]

Credibility, you choose:

1) The founder of a cult/hoax who was a science fiction writer who made a statement a decade before founding Scientology that the best way to get rich was to start your own religion, and who died on a yacht off coastal waters evading prosecution for income tax evasion, and whose cult requires you to pay to gradually receive all the information upto learning about Xenu the evil galactic ruler of 70 million years ago.

2) A man who preached salvation was freely available for all and was willing to die to make that available for all men.