A system of metaphor (pointing to a higher power) that one takes inside oneself as the truth and through its rules one aligns ones inner and outer behavior, submitting ones ego or will to the will of a higher power.
There's no scientific definition. A hymn. . . is a song of praise to God. I think there were three real goals with our hymns that made them seem more in line with traditional classical hymn writing than with the modern worship movement and differentiate us slightly. . .