At some time in the last thirty years, it mutated into "well, it is your belief in the cross that they recoil from" and then into a cross has no effect at all on a vampire. When Hollywood changed that, I washed my hands of them. Frank Capra is dead.
Yeah, I know.
And Lex Luthor didn’t start out as an eeeeeeeeevil corporate bastard.
The original Lex was a scientist.