GRATITUDE is a choice that becomes a habit. It is a major ingredient in the alchemy of transformation and is closely related to love... Gratitude creates a combustion of energy that powers our living cells. That's why all spiritual traditions teach the importance of gratitude. It certainly isn't because the deity needs any reassurance. Rather it's because when we are in the state of gratitude, we're affirming our faith in our own highest good and denying authority to the paralyzing, constricting energy of fear.
Everything is here for the same reason, for manifestation and celebration. But the humans articulate this. The others cannot articulate it reflectively. They can be a manifestation, but they cannot reflect on that. Humans can, therefore our role is to be spokespersons for the universe and to appreciate the universe as the context in which the Divine and human meet.