Avian Lore 2: The Polishing

I've read everything I could about avians, and most of the comments for revising or restating info about them. Something that I am caught up on is Kluex's commandments, specifically flight. Firstly, what is the definition of flight to avian? Secondly, many parts of avian religion revolve around flying, becoming able to fly, etc., but Kluex states in his commandments that this is against the avian religion. And if the idea is that only celestials are allowed to fly, who can say you are not one if you do fly? It's like as soon as you break that rule, you are exempt from it anyway. Unless I have the definition of flight wrong.