“Do not I fill the heaven and earth?” says the Lord. (Jeremiah 23:24)
How simply, strongly, and beautifully those words express the omnipresence of God.
God is in this and every place.
In Psalm 139 the psalmist says that God is equally in the length and breadth and in the height and depth of the universe.
In a word, there is no point of space, whether within or without the bounds of creation, where God is not.
Indeed, this is too vast to be comprehended by the narrow limits of human understanding. We can only say that God is as unbounded in His presence as in His duration and power.
He is said to dwell in heaven. But strictly speaking the Heaven of heavens can’t contain Him.
We cannot believe the omnipotence of God unless we believe His omnipresence. Nothing can act where it is not.