The omnipresence of God is grounded on the infiniteness of his essence. If God be infinite, he is omnipresent. Suppose him infinite, and then suppose there is any thing besides himself, and his presence with that thing, wherever it be, doth necessarily follow; for if he be so bounded as to be in his essence distant from any thing, he is not infinite.
John Owen, The Works of John Owen, ed. William H. Goold, vol. 12 (Edinburgh: T&T Clark, n.d.), 96.
Psalm 139:7–10 (ESV):
7 Where shall I go from your Spirit? Or where shall I flee from your presence? 8 If I ascend to heaven, you are there! If I make my bed in Sheol, you are there! 9 If I take the wings of the morning and dwell in the uttermost parts of the sea, 10 even there your hand shall lead me, and your right hand shall hold me.
Jeremiah 23:23–25 (ESV):
23 “Am I a God at hand, declares the Lord, and not a God far away? 24 Can a man hide himself in secret places so that I cannot see him? declares the Lord. Do I not fill heaven and earth? declares the Lord. 25 I have heard what the prophets have said who prophesy lies in my name, saying, ‘I have dreamed, I have dreamed!’