One of the great mysteries to me is that God created this world and yet He knew Adam & Eve would rebel against Him causing sin to come into the world. I wonder how many times the question has been asked, why did God allow that to happen, which can also go with the problem of evil that meaning have been struggling with over the centuries.
Yet, God, in His sovereignty knew what was going to happen and also had a rescue plan to redeem mankind. He foreknew that His only Son, Jesus, would be the one who would come to redeem us from our sin. God did not have to go through heaven with a long list of angels to see who would be the perfect sacrifice. He knew Jesus was it. The Bible says:
And if you call on him as Father who judges impartially according to each one's deeds, conduct yourselves with fear throughout the time of your exile, knowing that you were ransomed from the futile ways inherited from your forefathers, not with perishable things such as silver or gold, but with the precious blood of Christ, like that of a lamb without blemish or spot. He was foreknown before the foundation of the world but was made manifest in the last times for the sake of you who through him are believers in God, who raised him from the dead and gave him glory, so that your faith and hope are in God. (1 Peter 1:17-21)
Open Theism suggests that God is not sovereign and events that happen catch him by surprise which includes the Fall. If that was the case, then we are mistaken that our God is all powerful and we have no hope but in a god who freaks out when things go wrong. When sin came into the world, it did not catch Him by surprise. God chose Jesus before the world to redeem us. His plan was already in tact unlike a lot of our plans.