There's nothing wrong with snap judgements. The problem comes in labelling people based on those snap judgements. If I've understood you correctly, and if you truly have the gift of discernment, shouldn't you take the time to get to know people for who they truly are?

Aside from other people, however, what I'm really questioning is how you're viewing yourself right now. It's one thing to want to learn more about other faiths and to expand your knowledge about them. But the true ability to discern means you can examine each one and determine which one you believe most.

If you really believe you have the gift of discernment, don't cop out by taking the view that everything's right in some form or another.