Intelligence is just knowing things and being able to process things, so in theory knowing about religion would be intelligence, however in religion knowing the *significance* of things is much more important, so it should really be wisdom...

Low intelligence may mean you follow blindly, but ask the average religious person the reasoning for The Great Schism and they'll probably pull a blank. Ask an irreligious trivia expert and they'll probably be able to tell you about how it was a disagreement over some traditions and the powers of the pope and who it should be which resulted in Christianity splitting in two in the 11th century, but it would take wisdom to know why it was significant, and why Catholics/Orthodox have historically disliked each other less than either/Muslims, along with a bunch of other useful contextual information which is lost when regurgitating facts