There are plenty of different definitions of "Angel". It just depends on who you ask. If you actually encounter one, however, then you've got something more definite to go on...but don't expect anyone else to necessarily believe you! They won't if they are not inclined to, and that's perfectly okay, I guess. I mean, really, what difference does it make whether they believe you or not? None, actually. Same deal with flying saucers, ghosts, and anything else the least bit unusual that one may have encountered. Let the debunkers be happy in their unbelief, I say. They want a World that fits only what they already believe and nothing else. Okay, fine. You live in exactly the World you believe in as long as you keep believing in it. Sometimes direct experience can change that set of beliefs radically...but only for the one who has the experience! There will always be people who deny YOUR direct experience out of hand...because they KNOW it just can't be true. "I don't believe it's possible, so it can't be true. You couldn't have had that experience, and if you think you did, you are mistaken." Well, whoopee doo. Ignorance is the most impervious armour known to man. It admits no possibility that it has not itself already adopted.

And you do not have to belong to any religion to see an Angel...they're nondenominational. :-) Despite this, most organized religions seek to establish exclusive ownership over them. Sad, that's what is. Sad.