* God must learn, as He would not know what decisions people could make in the future.
* God could be wrong about something, as He has no way of knowing what decisions people could make at a later point in time. Whatever He plans could be thwarted.
* If open theism is true, then God cannot simply be all-knowing. If He is not all-knowing, then it is difficult to see how He can be all-powerful. You cannot say that God is omniscient (meaning that He knows all things) and then affirm that God does not know something in the very next breath. That is affirming A and not A at the same time in the same relationship. Consequently, it would be rather difficult to trust in the reliability of biblical prophecy. It would also be difficult to trust that God could accurately answer our prayers.
Even a cursory glimpse at Scripture is sufficient to expose the errors of open theism. The Bible outrightly states that God knows the future perfectly (Psalm 139:4; 16; Isaiah 46:9-10; Jeremiah 1:5; Matthew 26:34; 1 John 3:20). Nothing is beyond His comprehension (Psalm 147:5). Nothing is hidden from His sight (Hebrews 4:13). While proponents of open theism may adamantly contend that their system of thought does not undermine the sovereignty of God, that is precisely what this theology does. It flies right in the face of His glory and majesty. His thoughts are not our thoughts. His ways are not our ways. There are no limits to the depths of His wisdom. If open theism is true, then the God of the Bible would not be any different than the idols worshiped by pagans (Isaiah 41:22-23).