Yes, there is. Religion is a specific and at least somewhat organised collection of beliefs. So belief is an absolutely essential part of religion, but religion is not an essential part of belief. For example, someone might believe that microwaves are made by elven artificer wizards and heat food with magic. That's a belief, but it might or might not be part of a religion.
They dont have faith in it though. If you showed them how it really worked they would happily accept it. If they had faith in wizards you couldn't shake their belief and you would have a microwave wizard religion. i suppose belief is temporary but faith is permanent. So that would be the distinction.
Religion = solidified beleifs.
The longer they have been solidified the more legit the religion seems.
