Brahman is Atman and Atman is Brahman.

Love is the first and greatest commandment. It is said in the Vedas that Truth is One. It is so. But who is this One but Self? Self is always One without a second. It is said that Brahman is not Self but it is not so for there is only One Self. Oneself is Brahman and Brahman is Oneself and division there is none. The perception of division or otherness serves but the purpose not to feel alone. So it is. That which thou art is indeed the eternal Brahman.  Brahman experiences itself as Life diversified not to feel alone. Life diversified is Brahman itself. There is no separation. How could Brahman be outside itself when there is only Brahman? How could Oneself be outside itself when there is only Oneself? It is not possible. All that is here is Brahman; all that is here is Oneself. As to the perception of otherness; the cause is indeed loneliness aka aloneness. Aloneness is the cause and Companionship is the purpose. Life is Brahman desiring Companionship. Brahman is Self and Self is always One. Life is Oneself desiring Companionship. Companionship is a synonym for Love. Love is the purpose of Life for Life is Brahman desiring Love, i.e., Love is the purpose of Life for Life is Oneself desiring Love. Everything revolves around Love rightfully so for it is what Oneself desires; it is what Brahman desires. All that is here is Oneself desiring not to be alone; all that is here is Brahman desiring Companionship. There are not many selves, there are not two selves, there is only Oneself desiring Love which results in Oneself perceiving itself as two selves, as many selves, for Love. All is always G-d for there is only G-d desiring Love. Love is always the median to which Oneself aligns itself too. All this for Love; not to feel alone.
~ Wald