great question, this is a very good question
In my personal experience there are religions in all the universe and plains of existence. Its fascinating really. Upon entering all flags and symbols descend upon one, all sharing the same truth of Oneness (kingdom of heaven, brotherhood of men, Love Supreme.) This is why our earthly symbols are so good (the cross, etc.) The simpler the symbol the easier it is to spread and impart its precepts. The observation of a symbol is the downloading of all the knowledge of a symbol (telepathic knowledge, instant knowledge, is the means by which perception and sensation exists beyond the five agregates.)
My greatest teachers have been aliens, ('sky people', 'intergalactic brothers' 'dead ancestors', etc.) found in the heart. They are wise cause they are the most loving people you will ever encounter.