But Jesus would not entrust himself to them, for he knew all men. (NIV)
1. It is obvious from Scripture that Jesus did not know everything, for he grew in wisdom (Luke 2:52), and he did not know certain things (Matt. 24:36). Whenever the word “all” is used, the student of Scripture must be careful to ascertain from the context whether it means “all” in a totally inclusive sense, or whether it means “all” in a more limited sense (see note #5 on Col. 1:15-20). For example, 1 John 2:20 (KJV) says of Christians, “ye know all things.” Surely there is no Christian who actually believes that he knows everything. The phrase is taken in a limited sense of “all” according to the context.
2. Trinitarians explain the fact that Jesus did not know certain things by appealing to his “manhood” in contrast to his “Godhood,” or “God-nature.” However, when there is a verse that can be construed to mean that Jesus knows everything, they abandon that argument and say that his omniscience proves he is God. We think it is reasonable to assert that you cannot have it both ways. Either Christ did not know everything, or he did. There are very clear verses that say he did not, and no verse that actually says that Jesus did know everything the same way God does. When a verse seems at first to say Jesus “knew all men,” it should be understood in a limited sense according to the context, just as when Scripture says Christians “know all things.”
Trinitarians are aware that some verses say that Jesus did not know everything and others say he did. Rather than accept the common use of “all” in a limited sense, they press onward with their doctrine by asserting that Christ had both a God nature and a human nature within himself. They claim that the “God nature” knew everything, but the “human nature” was limited. This argument falls short on many counts. First, Jesus Christ was “made like his brothers in every way” (Heb. 2:17, et al.), and we are not “part God, part human,” or “fully God and fully man.” In order for the integrity of Scripture to be preserved, Jesus must actually be like we are, i.e., fully human.
Second, there is no place in Scripture where this doctrine of the “dual nature” of Christ is actually stated. Trinitarians are asking us to believe something they cannot prove from the Word of God. We, on the other hand, are asking them to believe something that we can read line by line in the Bible: that Jesus was flesh and bone, not spirit; that he was a man, and that he partook in our humanity. Third, the very concept involves a self-contradiction. God is infinite and man is finite, and so Christ would have to be a finite-infinite being, which we believe is inherently impossible. That is not the Jesus described to us in the Bible. No wonder Tertullian, an early Trinitarian, said, “Credo quia impossibile est” (I believe because it is impossible). We realize it is not only “impossible,” but also unscriptural, so we choose not to believe it.
3. Jesus needed to hear from God to know how to judge (John 5:30), and he knew all men the same way—by hearing from God.
4. In saying that Jesus knew all men, the Bible was confirming that Jesus was in touch with God just as were the prophets of old (but, of course, much more intimately). It was a common belief that prophets knew people’s thoughts (Luke 7:39, etc.), and it is substantiated in Scripture that God did show prophets what people were thinking. Nathan knew of David’s secret sin (2 Sam. 12:7). Ahijah knew what the wife of Jeroboam wanted, and who she was, even though he was blind and she was wearing a disguise (1 Kings 14:4 and 6). Elijah knew that Ahab had committed murder by framing Naboth (21:17-20), and he knew the information that the king of Israel wanted to know (2 Kings 1:1-4). Elisha knew that Gehazi was lying and knew of the greed in his heart (2 Kings 5:19-27). Daniel knew Nebuchadnezzar’s dream, even though Nebuchadnezzar had not revealed it to anyone (Dan. 2:5 and 28ff). By saying that Jesus knew all men, Scripture confirms that he was, like the prophets of old, in communication with God.
Morgridge, pp. 124-126