Pretty simple really...If God knows something will happen, does it have to happen?
How does that question not make sense? Seems like a yes or no thing.
Yes, if God knows something will happen, then it will happen.
Are you asking if God could be made a liar? What He has proclaimed will be. He knows all that is past, present, and future.
Are you asking if man can prevail upon Him to change His mind? There is some suggestion of that in the scriptures, yet He always knows what He is doing.
Example: Satan has set his will against God & will ultimately be dispatched to the Lake of Fire, which burns eternally. So, if I pray that Satan will repent, be reconciled to God, and return to heaven, will it happen? No, because that would make the Word of God untrue. And, God is Truth.