The most beautiful that I know is that of a Gnostic philosopher: "God is Love, but Love itself cannot be perfect unless it has those upon whom it can be lavished and by whom it can be returned.

Therefore He put forth of Himself into matter, and He limited His glory, in order that through this natural and slow process of evolution we might come into being; and we in turn according to His Will are to develop until we reach even His own level, and then the very love of God itself will become more perfect, because it will then be lavished on those, His own children, who will fully understand and return it, and so His great scheme will be realized and His Will, be done." At what stupendous elevation His consciousness abides we know not, nor can we know its true nature as it shows itself there.

But when He puts Himself down into such conditions as are within our reach, His manifestation is ever threefold, and so all religions have imaged Him as a Trinity.

Three, yet fundamentally One; Three Persons (for person means a mask) yet one God, showing Himself in those Three Aspects.

Three to us, looking at Them from below, because Their functions are different; one to Him, because He knows Them to be but facets of Himself.
All Three of these Aspects are concerned in the evolution of the solar system; all Three are also concerned in the evolution of man.