Oh noes! Generic crazy conspiracy theorist loon was right!
Just in case there was any doubt that superhero comic books were a Jewish conspiracy....
(Not that that is in any way a bad "Thing".)
There was a minor buzz about this a while back due to a New York Post article a while back (which seems to have gone down the memory hole) but the '76 date on this Kirby sketch should put to rest the notion that this was a recent revisionist development.
Much more on this topic here.
Oh, and it gives me considerable pride (and astonishment) to point out that Superboy and Supergirl are Methodists. (Superman is officially as well but he also practices the "Kryptonian religion" which, given what I know about his creators likely involves the Torah.)
Update: Yes, I know that Ben Grimm's religion is hardly news to FF fans but there seems to be some concern by some pathetic weeaboos that this is PC revisionism.