If God knew everything beforehand, he would be trapped in his fore-knowledge and would have no free will.
It is generally assumed by Christians that God is all-knowing. We say insistently God is omniscient. Peter said to Jesus: “We understand that you know everything.” (John 16:30). However, there are things Jesus did not know. He did not know a fig-tree did not have figs. (Mark 11:13). He did not know the time of his return. (Mark 13:32).
Just as Jesus relinquished provisionally certain attributes of his divinity when he became a man, including the ability to be in two places simultaneously; even so God has relinquished certain divine attributes in order to interact with us. This includes the fore-knowledge of the moral choices of men.
Indeed, God declares “the end from the beginning, and from ancient times things that are not yet done.” (Isaiah 46:10). Nevertheless, there are things about men that God has decided not to know, except through investigation and research.
Free will
God cannot be all-knowing when some things go against his will. He cannot be held responsible for the evil in the world. Jesus asks us to pray that God’s will be done precisely because God’s will is not done on earth as a rule.
If God knew everything beforehand, he would be trapped in his fore-knowledge and would have no free will. But we know God has free will because man has free will, and we are created in God’s image and likeness. God’s omniscience permits men the free will to make independent moral choices. He says to us: “I have set before you life and death, blessing and cursing; therefore choose life.” (Deuteronomy 30:19). The choice is ours.
In order for an omniscient God to exercise his free will in time as opposed to eternity, he has to stop being completely omniscient. Therefore, the God of the bible is a “watcher of men.” (Job 7:20). He predicts our actions essentially by “searching” our hearts and minds. (Psalm 7:9). He “discovers” our hidden sins. (Psalm 44:20-21). He tests us in order to know us.
In order to know David, God had to study him. David confirms this, saying: “O Lord, you have examined my heart and know everything about me.” (Psalm 139:1). The Lord himself says: “I the LORD search the heart and examine the mind, to reward a man according to his conduct, according to what his deeds deserve.” (Jeremiah 17:10).
When the princes of Babylon came to visit Hezekiah: “God withdrew from him, in order to test him, that He might know all that was in his heart.” (2 Chronicles 32:31). The same applies to the children of Israel in the wilderness. Moses says God tested them: “to know what was in (their) heart, whether (they) would keep His commandments or not.” (Deuteronomy 8:2).
According to Jesus, the judgment of God is not predetermined. The Father waits to see how we act in order to decide how to judge us. Therefore, Jesus warns: “With what judgment you judge, you will be judged; and with the measure you use, it will be measured back to you.” (Matthew 7:2).
God’s self-limitations
Job says: “(God) knows the way that I take.” (Job 23:10). But this usually happens after he becomes acquainted with us and sees a pattern in our behaviour. Thus, Jesus knew Peter would betray him through a combination of the foreknowledge of his trial and the observation of Peter’s inclinations. Similarly, Jesus studied Judas even before calling him, just as he did Nathanael. (John 1:47-48). Therefore, he knew Judas would betray him once the opportunity arose.
God is not cynical or pessimistic. Therefore, he did not expect men to become evil. When this happened: “The LORD was sorry that He had made man on the earth.” (Genesis 6:6). God did not anticipate that men would plan to build Babel. When we did: “The LORD came down to see the city and the tower which the sons of men had built.” (Genesis 11:5). God did not even have foreknowledge that Abraham would offer up Isaac. Therefore when Abraham did, God said to him: “Now I know that you fear God, since you have not withheld your son, your only son, from me.” (Genesis 22:12).
Because God is pure in mind, he did not envisage the evil actions of men before they happened the very first time. He says of Judah: “They built the high places of Baal which are in the Valley of the Son of Hinnom, to cause their sons and their daughters to pass through the fire to Molech, which I did not command them, nor did it come into My mind that they should do this abomination, to cause Judah to sin.’” (Jeremiah 32:35).
As a matter of fact, God does not personally oversee everything done everywhere. He has angels on assignment who give him regular reports. Thus, an angel pointed out other angels to Zechariah and said: “The Lord has sent them to patrol the earth for him.” (Zechariah 1:10). At other times, God decides to confirm their reports personally. Thus, he said to Abraham concerning Sodom: “I will go down now and see whether they have done altogether according to the outcry against it that has come to me; and if not, I will know.” (Genesis 18:21). When Abraham interceded for the city, God said to him: “If I find in Sodom fifty righteous within the city, then I will spare all the place for their sakes.” (Genesis 18:26).
Conditional promises
Many of God’s promises are contingent upon our conformity to his will. Samuel says: “(God) is not a man that he should change his mind.” (1 Samuel 15:29). But on a number of occasions, God is said to have changed his mind in the scriptures in annoyance at the contravention of his will. Thus, the promise he made that the house of Eli would minister before him forever was revoked: “I, the LORD God of Israel, promised in the past that your family and your clan would serve me as priests for all time. But now I say that I won’t have it any longer!” (1 Samuel 2:30).
This indicates God does not predetermine the will of men. Indeed, he says: “If at any time I announce that a nation or kingdom is to be uprooted, torn down and destroyed, and if that nation I warned repents of its evil, then I will relent and not inflict on it the disaster I had planned. And if at another time I announce that a nation or kingdom is to be built up and planted, and if it does evil in my sight and does not obey me, then I will reconsider the good I had intended to do for it.” (Jeremiah 18:7-10).
This explains why the devil could challenge God concerning Job. (Job 1:9-11). If God could predetermine Job’s eventual faithfulness, the challenge would have been pointless. Indeed, if God predetermines everything, prayer would be pointless. But when Moses interceded for Israel: “the LORD relented from the harm which He said He would do to His people.” (Exodus 32:14). When Hezekiah prayed, God rescinded his earlier decision to take his life. (2 Kings 20:5-6).
Knowledge of God
The holiness of God precludes him from knowing certain people. God does not know sinners because he does not know evil. “The Lord knows the way of the righteous.” (Ps 1:6). He does not know the way of the wicked. “He knows those who trust in Him.” (Nahum 1:7). He does not know those who don’t.
Therefore, in the Day of the Lord, many highfalutin Christians will discover the Lord does not know us. Jesus warns: “On that day many will say to me, ‘Lord, Lord, did we not prophesy in your name, and cast out demons in your name, and do many mighty works in your name?’ And then will I declare to them, ‘I never knew you; depart from me, you evildoers.’” (Matthew 7:22-23).