Stephen Charnock on God’s omniscience:

God is essentially everywhere present in heaven and earth. If God be, he must be somewhere; that which is nowhere, is nothing, since God is, he is in the world; not in one part of it; for then he would be circumscribed by it: if in the world, and only there, though it be a great space, he were also limited. Some therefore said, “God is everywhere, and nowhere” [Chrysostom]. Nowhere, i. e. not bounded by any place, nor receiving from any place anything for his preservation or sustainment. He is everywhere, because no creature, either body or spirit, can exclude the presence of his essence; for he is not only near, but in everything (Acts xvii. 28): “In him we live, and move, and have our being.” Not absent from anything, but so present with them, that they live and move in him, and move more in God, then in the air or earth wherein they are; nearer to us than our flesh to our bones, than the air to our breath; he cannot be far from them that live, and have every motion in him. The apostle doth not say, By him, but in him, to show the inwardness of his presence. As eternity is the perfection whereby he hath neither beginning nor end, immutability is the perfection whereby he hath neither increase nor diminution, so immensity of omnipresence is that whereby he hath neither bounds nor limitations. At he is in all time, yet so as to be above time; so is he in all places, yet so as to be above limitation by any place. It was a good expression by a heathen to illustrate this, “That God is a sphere or circle, whose center is everywhere and circumference is nowhere.” His meaning was, that the essence of God was indivisible; i. e. could not be divided. It cannot be said here and there the lines of it terminate; it is like a line drawn out in infinite spaces, that no point can be conceived where its length and breadth ends. The sea is a vast mass of waters; yet to that it is said, “Hitherto shalt thou go, and no further.” But in cannot be said of God’s essence, hitherto it reaches and no further; here it is, and there it is not. It is plain, that God is thus immense, because his is infinite; we have reason and scripture to assent to it, though we cannot conceive it. We know that God is eternal, though eternity is to great to be measured by the sort line of a created understanding. We cannot conceive that vastness and glory of the heavens, much less that which is so great, as to fill the heaven and the earth, yea (1 Kings viii. 27), “not to be contained in the heaven of Heavens.”

—Stephen Charnock, The Existence and Attributes of God (Baker Books, 2005), 1:366–377