Sorry for the delay my friend, I have been quite busy.
God's knowledge is infinite, but there is no verse in the Bible that tells us that God knows everything. At the same time, there are many Bible passages which indicate that He does not know some things.
Consider the promise of God to forget the sins He has forgive. In several verses God says,
"I will remember their sins no more"(e.g., Heb. 8:12). Of course, this can be considered a figure of speech, but it is also possible that God can sovereignty decide to remove from His own consciousness the sins He has forgive. In other words, it is possible that a perfect God can perfectly forget. Maybe we should take His words literally.
The Bible also tells us that God searches the hearts of people, which implies that God is seeking to discover things that He does not know. Further, God tests people to see what is in their hearts. Concerning Hezekiah we are told:
....God left him alone only to test him, That He might know all that was in his heart. (II Chron. 32:31)
Deuteronomy, chapter 8, tells us about God allowing the Hebrew people to wander in the wilderness for 40 years:
"...that He might humble you, testing you to know what was in your heart, whether you, would keep His commandments or not." (Deut. 8:2)
For another example of this testing to know, consider God's work in the life of Abraham. God told Abraham to kill his own son and offer him as a sacrifice (Gen. 22). In obedience, Abraham took his son up to the moutain and prepared him for the sacrifice, but God stopped Abraham right before he killed Isaac. God spokle through an angel:
He said, "Do not stretch out your hand against the lad, and do nothing to him; for now I know that you fear God, since you have not withheld your son, your only son, from me." (Gen. 22:12)
God said,
"...now I know...." Didn't God know before this? If we believe God's words literally, then we have to answer, "No."
Other Bible verses (e.g., 1 Sam. 16:7; 1 Chron. 28:9; 1 John 3:20) tell us that God can see and know everything in the heart of a person, but how does this fit with the idea that God tests people to see what is in their heart? This is understandable if we consider the possibility that the human heart is able to initiate thoughts and desires. God can see into the heart of every person, but ideas that are not in the heart of a person today may arise tomorrow. Since God is moving through time with us, He continues watching, searching and testing.
No one knows for certain how the dynamics of God's awareness work, but let me propose a possibility. Perhaps God already knows if you are going to get in a car wreck tomorrow. He knows the exact time, location, and every minute detail of the even.t However, it may be that God will still be watching to see what is going to come out of your mouth the instant of the crash. Maybe He has created humanity with a free will and the ability to bring things forth from our own hearts without His predetermination of preknowledge. I am not saying this is true, but it is certainly a possibility because it fits with how we see God dealing with others in Scripture.
We must keep in mind that God is sovereign (He can do whatever He wants to do), and therefore, He can decide to not know certain things. On the other hand, if we say that God is omniscient, w
e maybe be denying his Sovereignty- we are saying that God has to know everything and He has no freedom to decide to not know all things.
If God already knew what every person was going to do, say, or pray, then He never would have the opportunity to respond and change His mind. Since the Bible tells us that God changes His mind, and nowhere does it tell us that He knows everything, we must question the traditionally accepted idea of omniscience.
Some of you might say that the examples I have given of God not knowing certain things are insignificant compared with the vast knowledge which God does have. Hence, they would be comfortable ignoring these minor "unknowns" and continue to describe God as omniscient.
I agree that God's knowledge is so vast that it is beyond our comprehension. He knows every blade of grass on the earth and every molecule on Jupiter. However, to have a biblical accurate understanding of God's nature, we must be careful to use biblical terms. God's knowledge is infinite. That is what the Bible teaches- no less, no more. Yet it is alarming to learn how many Christians will fight for a doctrine which is not in the Bible. They will fight as if God needs someone to defend Him. They will fight for something which- whether it is true or not- God chose not to reveal about Himself.