I used to find it difficult to reconcile God's being as pure light. The light and darkness we perceive in the world is part of the play of opposites. Darkness can be considered as far from God and light as closest to God. God then is Pure Light without darkness.
But how can God (aka Consciousness, the Self, Brahman, the Infinite One) be a Pure Light without end. If we consider the light that we perceive, then there would be no darkness. Light without end cannot allow darkness to appear. This seemed to be a problem, and it's similar in some ways to the question of evil: how can God, being Pure Light and Love, allow evil to continue in the world. There is an answer to this: darkness and evil do not appear. There is only God.
That needs some explanation, as most people will have experienced darkness and evil. The light of God is Pure Clarity. It is a perfect, pure nothingness. Darkness can only seem to appear by the clouding of this clarity. But the clouding is itself God. So it is not really clouding, it is still God.
Similarly with evil, there is only God. If God harms God, is that evil? We can call it evil if we want, but really there is only God. Both darkness and evil seem to be God far removed from the true nature of God. This is how the world appears, by the 'breaking of the body of God' into apparently separate opposites. God's Light only seems to be separated into light and darkness. God's Love only seems to be separated into love and hate.
Darkness is still light, only seeming to be separated and distant from God. Evil is still the quality of love, only seeming to be separated and distant from God. The world is created through the appearance of the separating of God's Infinite Oneness.
Similarly, we think of ourselves as separate and distant from God. But God is infinite and omnipresent. None are outside God. It only seems that the world is separate from God. In truth God pervades the world. God is Consciousness, seemingly at the heart of our being, yet truly the whole of our being. There is only the Infinite One.