In a nutshell open theists say, “God can’t know the future.” Their argument is, “God knows everything that can be known. But the future cannot be known. Therefore, God does not know the future.” Right off the bat, I mean out of the gate, there are a couple of glaring problems with their argument. One is they have subjected God to His creation. According to this argument, God is now limited in what He can know, by linear time. God transcends time. He is above time. Sure we experience Him in time, because we are finite creatures existing in His creation. In that creation He has given us a defining dimension called time. This in no way limits His knowledge. God exists in an ageless age we call eternity. You can think of it as an infinite instance where all things exist and cease to exist at God’s sovereign will.
The next big problem with open theism is that it negates most of the Bible. Think about it, if God cannot know the future as a finite reality, determined by His decreed or ordained will, how did the prophets speak God’s words, in such a way where the actual determined future, took place in accord with His will, to become historical narrative? When they spoke, what He told them about the future. It came about exactly as He told them. What was given as prophecy did not simply become reality as it was fulfilled. It was determined reality the moment God decreed or ordained it. As they experienced it in linear time, it may have seemed like the prophecy was coming true experientially, but in fact it was known by God as He was the source of it. The Bible is a progressive revelation of God’s word. The actual realities that hadn’t occurred yet to the prophets were no less actual. Prophecy once fulfilled and recorded is increased by the quality of becoming historical narrative.
Most open theists hold the view they do because they have reduced God to a man like creature. They do this because they cannot justify the existence of evil. They fail to study theodicy in a Biblically consistent, God centered, and God honoring way. It honors God to be honest, and to glorify Him. It does not honor Him to elevate mankind’s concepts of justice, good, and evil.
Here is another definition of open theism, “Open Theism is the thesis that, because God loves us and desires that we freely choose to reciprocate His love, He has made His knowledge of, and plans for, the future conditional upon our actions. Though omniscient, God does not know what we will freely do in the future.”
I would not disagree with most of the first part. God does love the elect and does desire that they would choose Him. Of course He does not love the ones who will reject Him unto their mortal ends. They will die in their sins. I would vehemently disagree with their assertion that, “God has made His knowledge, and plans for, the future conditional upon our actions.” I believe that I have demonstrated through use of the example of Biblical prophecy how foolish this viewpoint is. The next statement they make is, “Though omniscient, God does not know what we will freely do in the future.” This defies logic. The definition of omniscient is to know all things. How could He not know, what is actual reality in the future, and still be said to know all things? He would not be omniscient anymore. Knowledge is a thing. It is a created thing. We only know things in a corrupt way. We are finite creatures made by God. We have a very limited ability to perceive reason, understand, recall, and communicate. All of these attributes of ours are affected by sin and our finite existence as creatures. We call this the noetic effect of sin. God, as the creator of all things, knows perfectly everything about the things He created. This being said, He is the source of all knowledge and knows it perfectly. What can be known is known by Him in totality and perfection. That is omniscience. Not this convoluted notion of pseudo-omniscience the open theist proposes. Again, they do this because they have a low view of God and cannot explain why evil exists without besmirching God. Their reaction to this is to reduce God and His knowledge to something more akin to a creature rather than the sovereign Creator.
They start with some false presuppositions that necessitate and precipitate the heresy of open theism. The presupposition, that God limits His knowledge, to what end, so that we can make a free choice? It would be laughable if it weren’t so sad. The presupposition, that it is necessary for God to limit His knowledge, so that we can choose Him is equally as offensive. I exhort you all to flee from open theism. If you don’t understand some things of God, like how there can be a good God who lets evil exist, or how He can be in control of everything and use sin sinlessly, just trust God and lean not on your own understanding. One day you might mature to the point where you do understand these things. There is no need to justify them wrongly and attribute to God attributes that are not true.