It means he is “all-knowing.” He absolutely and totally and exhaustively knows himself, his creation, and you.
This attribute or perfection is often considered incommunicable or “unshareable” or “non-transferrable” to us humans, while others classify it as communicable (in part). This post sees it as partly communicable, because we also have knowledge, but extremely limited.
Let’s begin with some definitions.
What do theologians say?
Though I am not of the Reformed faith, I can still learn from them. Herman Bavinck reminds us that to be strictly accurate and biblical, there is no foreknowledge with God because even the “future” is vividly before his eyes:
Consequently, strictly speaking, it is a mistake to speak of divine foreknowledge; there is only one knowledge of God. With him there are “no distinctions of time.” [He quotes Augustine]: “For what is foreknowledge if not knowledge of future events? But can anything be future to God, who surpasses all times? For if God’s knowledge includes these very things themselves, they are not future to him but present; and for this reason we should no longer speak of God’s foreknowledge, but simply of God’s knowledge.” (Reformed, p. 199)
Another Reformed theologian, Louis Berkhof, writes:
The knowledge of God may be defined as that perfection [attribute] whereby He, in an entirely unique manner, knows Himself and all things possible and actual in one eternal and most simple act (p. 66, emphasis original).
Berkhof goes on about the extent of omniscience, in contrast to what humankind knows:
The knowledge of God is not only perfect in kind, but also in its inclusiveness. It is called omniscience, because it is all-comprehensive. … God knows himself and in Himself all things then come from Him (internal knowledge). He knows all things as they actually come to pass, past, present and future, and knows them in their real relations. He knows the hidden the hidden essence of things, to which the knowledge of man cannot penetrate. He sees not as man sees, who observes the outward manifestations of life, but penetrates to the depths of the human heart. Moreover, He knows what is possible as well as what is actual; all things that might occur under certain circumstances are present to his mind (p. 67).
Renewal theologian J. Rodman Williams writes:
God’s knowledge is not that acquired through reasoning and reflection, nor accumulated through experience and verification. God is not a learner. … It is not that God is self-taught, but rather His mind encompasses all knowledge. Moreover, since God is the creator of all things in the universe—from the minutest particle in an atom to the largest star, from the smallest thing alive to human beings made in His image, he knows every aspect of His creation. (Renewal, vol. 1, p. 73)
Wayne Grudem, who admires and often borrows from Berkhof, writes:
God’s knowledge may be defined as follows: God fully knows himself and all things actual and possible in one simple and eternal act. (p. 190, emphasis original)
Norman Geisler is clear about the definition of omniscience, which does not include contradictory things:
Historically the omniscience of was a straightforward doctrine: God knows everything—past, presence, and future. He knows the actual and the possible; only the impossible (the contradictory) is outside the knowledge of God. (p. 496)
Can God do and know contradictions? No, he is too wise to engage in foolish thinking.
This attribute or perfection of God means that he knows everything about every knowable thing, past, present and future, actual or possible, and nothing is unknown and hidden from him.
What do the Scriptures say?
I use the NIV here. If you would like to see the following verses in many translations or in their contexts, please go to biblegateway.com.
God knows his creation thoroughly:
I know every bird in the mountains, and the insects in the fields are mine. (Ps. 50:11)
His creation includes humankind:
You have searched me, LORD, and you know me. You know when I sit and when I rise; you perceive my thoughts from afar. You discern my going out and my lying down; you are familiar with all my ways. Before a word is on my tongue, you, LORD, know it completely. You hem me in behind and before, and you lay your hand upon me. Such knowledge is too wonderful for me, too lofty for me to attain. (Ps. 139:1-6)
God’s knowledge is unlimited:
Great is our LORD and mighty in power; his understanding has no limits. (Ps. 147:5)
No one can fathom it:
The LORD is the everlasting God, the Creator of the ends of the earth. He will not grow tired or weary, and his understanding no one can fathom? (Is. 40:28)
God sees us in secret and answers our prayers:
Then your Father, who sees what is done in secret, will reward you. (Matt. 6:4, 7)
For your Father knows what you need before you ask him. (Matt. 6:8)
Once again Jesus affirms that God’s knowledge extends to small creatures and us.
Are not two sparrows sold for a penny? Yet not one of them will fall to the ground outside your Father’s care. And even the very hairs of your head are numbered. (Matt. 10:29-30).
In the above verse, our hairs being numbered speaks of intimacy.
In the next three verses, Jesus is said to know everything:
But Jesus would not entrust himself to them, for he knew all people … for he knew what was in each person. (John 2:24, 25)
Peter said, “Lord, you know all things; you know that I love you.” (John 21:17b)
And here is a doxology, an expression of praise:
Oh, the depths of the riches of the wisdom and knowledge of God! How unsearchable his judgments, and his paths are beyond tracing out! (Rom. 11:33)
Nothing is hidden from God:
For the Word of God is alive and active and sharper than any two-edged sword, it penetrates even to dividing soul from spirit, joints and marrow; it judges the thoughts and attitudes of the heart. Nothing in all creation is hidden from God’s sight. Everything is uncovered and laid bare before the eyes of him to whom we must give account. (Heb. 4:12-13)
More Scriptures about omniscience:
God is all-knowing (Is. 46:10; 1 John 3:20).
His knowledge of us precedes our birth (Ps. 139-15-16; Jer. 1:5).
God knows our needs (Ps. 103:13-14; Matt. 6:31-32).
Little things do not escape his notice, even the hairs on your head (Matt. 10:29-30 // Luke 12:7).
God cannot be taught by humans (Job 21:22).
God knows everything about his creation (Job 38-39).
Jesus knew God’s will completely (John 2:25; John 4:16-18; John 6:64).
All knowledge is hidden in Christ (Col. 2:3).
So you do not believe in open theism?
This doctrine says that God does not know what free creatures will choose in the future. Open theism affirms that God knows all truths that can be known, but there are some truths that have not yet occurred in an indeterminate, open future, and God does does not know these possible truths that have not occurred or happened or will never happen.
The Bible, as noted, says that God understands the open future. He knows all possibilities that could have been chosen by free creatures. He is not limited to knowing the choices that some free creatures do make. He knows everything about everything and all possible options, chosen or not chosen by free creatures. And he knows what would have happened if his free creatures had not chosen it.
My point is that God knows everything about everything, even the nonchoices that free creatures did not make but could have made, had they chosen to do so, as the options in life presented themselves.
God lives outside time, in eternity, and he sees the end from the beginning in our time. His knowledge is exhaustive of everything within time (and outside of time). This does not mean, however, that his knowledge fixes and determines everything. I don’t conflate his knowledge with omni-causation (God causes everything) which means that God orders or causes everything, as strong Calvinists (hyper-Calvinists) believe. I stand between the two views of open theism and this brand of Calvinism. But I am not able to draw the line between the two with mathematical precision (and I doubt you are too).
Though I taught Phil 101 at a community college for about a decade, I do not like epistemology, and we never dived deeply into open theism. So that’s the best I can do. I saw online all sorts of encyclopedia articles about it, and no doubt Christian philosophers who believe as I do–in God’s exhaustive omniscience–have youtube videos on it.
I wrote this post about God’s omniscience just to learn traditional theology. I am always learning. Check out the other vids from Christian philosophers who love these deeper issues. I prefer to stick with the clear statements of Scriptures, as noted above (not the endless scenarios of “what if ….”)
How do I know God better?
Psalm 147:5 says: “Great is our LORD and mighty in power; his understanding has no limits.” The next verse goes on to say: “The LORD sustains the humble, and casts the wicked to the ground.” And Heb. 4:13, just now quoted, says, “we must give an account.”
God’s total and comprehensive and absolute and exhaustive knowledge is personal to us. It can elicit in us the fear of the Lord. We can do nothing without his knowing about it—good or bad.
“The eyes of the LORD are everywhere, keeping watch on the wicked and the good” (Prov. 15:3). “I obey your precepts and your statutes, for all my ways are known to you” (Ps. 119:168). The verses quoted from Matthew’s Gospel reminds us that God cares for us and rewards as well as disciplines us and implements justice.
On the other hand, God’s knowledge can bring comfort. God declared to the children of Israel that he knew their going through the desert and the Lord had been with them, so they lacked nothing (Deut. 2:7). God understands what we are going through, our personal deserts and wildernesses. God’s love and knowledge can be combined, pastorally speaking. God knows you and loves you anyway! This truth going into our hearts can bring deep calm and assurance to the believer.
ARTICLES IN SERIES “DO I REALLY KNOW GOD?”
Do I Really Know God? He Is Omniscient