“That God is omniscient is not only taught in the Scriptures, it must be inferred also from all else that is taught concerning Him. God perfectly knows Himself and, being the source and author of all things, it follows that He knows all that can be known.
And this He knows instantly and with a fullness of perfection that includes every possible item of knowledge concerning everything that exists or could have existed anywhere in the universe at any time in the past or that may exist in the centuries or ages yet unborn.
God knows instantly and effortlessly all matter and all matters, all mind and every mind, all spirit and all spirits, all being and every being, all creaturehood and all creatures, every plurality and all pluralities, all law and every law, all relations, all causes, all thoughts, all mysteries, all enigmas, all feeling, all desires, every unuttered secret, all thrones and dominions, all personalities, all things visible and invisible in heaven and in earth, motion, space, time, life, death, good, evil, heaven, and hell.
Because God knows all things perfectly, He knows no thing better than any other thing, but all things equally well. He never discovers anything, He is never surprised, never amazed.
He never wonders about anything nor (except when drawing men out for their own good) does He seek information or ask questions.
God is self-existent and self-contained and knows what no creature can ever know Himself, perfectly. ‘The things of God knoweth no man, but the Spirit of God.’
Only the Infinite can know the infinite.”
–A.W. Tozer, The Knowledge of the Holy (New York: HarperCollins, 1961/1978), 56-57.