In describing God, we might begin by saying He’s all powerful, infinitely so, as we say — omnipotent (Re 19:6): He does as He pleases (Ps 115:3); nothing is too hard for Him. (Ge 18:14) He’s the Creator, fashioning time and space ex nihilo, and gives us no indication that this was the least bit challenging for Him; it’s hard to imagine a more immensely powerful act.
We might also describe God as all knowing, omniscient: He is aware of and understands all things. (1Jn 3:20) He’s intimately familiar with all His works (Ac 15:18), not just that they exist, or will exist, but every detail about each one of them: every word that will ever be spoken (Ps 139:4); the number of hairs on every head (Mt 10:30), the names of all the stars (Ps 147:4), He might as well know every grain of sand by name. If He knows such things, it’s hard to conceive of something He might not know.
We might also claim that God is omnipresent, that He’s everywhere all the time. This may seem obvious, given the above; if God created time and space itself, perhaps it stands to reason that He’s ever present throughout all Creation.
Yet this doesn’t appear as easy to prove from scripture; a quick internet check reveals that the many scriptures offered to support this concept don’t quite get us there. What if God created everything to be self-sustaining and then stepped away to let it run all on its own? What scriptures apply here, not just that God is everywhere we are, but that He occupies every space, every possible location?
Scripture describes God the Father as above all, and through all, and in you all. (Ep 4:6) The idea of through all, as in permeating and surrounding everything in existence, seems to get at this idea, as well as above all, which appears to convey transcendence, beyond everything, higher than the highest, lower than the lowest, farther than the farthest, etc. How can one be above all and through all and not also be everywhere — omnipresent? Trying to decouple these phrases and what they convey seems academic at best.
This above all and through all is consistent with the idea that Christ holds everything together: by Him all things consist (Col 1:17), He upholds all things. (He 1:3) To be holding everything together, God must be present in some way, sustaining everything and giving it substance to continue to exist, beholding and observing (Pr 15:3), engaging everything and sovereignly controlling it all. (Ep 1:11)
Yet some might argue that God can’t be in Hell, that Hell must be the absence of God because God is Love. (1Jn 4:16) This may be the strongest argument against the omnipresence of God. What do we say?
What should we expect to happen if love and mercy actually are freely offered in Hell, with open arms and a tender call to repent? (Ro 10:21) Wouldn’t God’s love be continually and vehemently rejected by those suffering there? Wouldn’t the wicked continue to willfully choose their fiery end rather than repent and submit to God? (Re 16:11) and do so every moment for all eternity? (Pr 27:22)
Perhaps the problem in Hell isn’t God at all; perhaps the problem is Man. And perhaps the key to resolving many mysteries we see in God’s character and behavior lies here as well, in the Depravity of Man. (Je 17:9)