>>18057431
>His only gimmick was being religious and saying "erino".
That's what people point to when they mean Flanderization. Watch season 1 or 2 episodes. Flanders is basically just a dull, nice, boring neighbor. The ultra Christian stuff came later (even the Simpsons regularly attended church in the early seasons) and the "High diddly ho, neighberino" went from a one off joke to being his catchphrase and whole style of speaking.