#Religion: Jalal al-Din Rumi, by far the most prestigious sufi in Islam’s entire history, explained this concept as such:

Remember the famous utterance of al-Hallaj, “I am God.” People think that to say “I am God” is a claim of great pretense and spiritual arrogance. It is actually a claim of extreme humility. “I am God” means “I do not exist.” He is all, everything is He, existence is God’s alone. I am without existence, pure non-existence. I am nothing.” “I am God” is not a claim of great pretension, it is a claim of extreme humility. There is more humility in this than any supposed claim to greatness, but people do not understand the inner meaning. When a man acknowledges his servitude to God, he is aware of his being a servant. He may see himself as a devoted servant of God, but he still sees himself and his own actions as apart from the one reality of God. He is not drowned in the Ocean of Divine Unity. Drowned is he in whom there is not separate motion or mobility. Drowned is he whose movement is the movement of the water. And so it is with the enlightenment ones, those who declares, “I am God.” Anyone who says “I am the servant of God” asserts the reality of two existences, one for himself and the other for God. But he who says “I am God” — and has realized the deepest levels of unity within his being — has seen through the illusion of his existence. He knows from the experience of unity that his own separate existence is nothing but an illusion. Knowing that, he casts its former selfhood upon the winds of oblivion. (Rumi, Hearts bear witness one to another, in The Complete Discourses of Jalal al-Din Rumi, discourse 11, p. 75, ed. Louis Rogers)