This has two explanations: There is one Power in the Universe, and that Power is Love. This one Power is that Universal Energy which we have been calling Life or Light. This is a naming of it, it is not a description of it. It is this same Power which gave rise to the Universe producing the positive and negative vibrations and atoms which directly or indirectly gave rise to all planes and all forms.
Now what is or was this Power? It is the Power which comes from letting go, from losing the self, the Power which arises from non-attachment to personality. And what is that Power? It is nothing but Love. God so loved, that He created, and He so loved the world that He had created that He permitted His Power to appear in fullness in a human being. This is the mystery of Christhood. That gave all men the opportunity first to witness, and then through example to attain to, the fullness of this Power of Love while in the human body in the physical world. This was the very purpose of creation.