He knew in advance that they would.
I'm saying that he may not have known for sure just like he didn't know for sure that Abraham would obey him until Abraham actually started to offer up Isaac.
He said, “Do not lay your hand on the boy or do anything 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
That would be like my "testing" my four-year-old daughter to see if she can lift a Lincoln Continental over her head.
Only if God truly knew with certainty that Adam and Eve would definitely fail. He even prepared a contingency plan in the event that they did disobey him. He would restore man into a right relationship with himself by becoming like us and dying in our place for our sins.
Destroyed, then - whatever term applies that amounts to "made not to exist any more".
(Or, better yet, don't create in the first place beings that you know will rebel and wreck your future relationship with humans.)
It's risk God took in providing created rational beings with a free with to chose this or that, good or evil. He could have made humans like robots who only did his will and desire all of the time. What kind of relationship is that?
I'm saying God didn't know for sure. It was only one possibility that they would disobey. The other possibility was that they wouldn't disobey.
Prolonging in a war that you can win in an instant - with literally no effort - is idiotic.
He is not prolonging it indefinitely. The end will come and we all will be judged by him.
Here is a reason below for his "prolonging". He likely has more that I simply am not aware of.
2 Peter 3:7 But by the same word the present heavens and earth have been reserved for fire, being kept until the day of judgment and destruction of the godless. 8 But do not ignore this one fact, beloved, that with the Lord one day is like a thousand years, and a thousand years are like one day. 9 T
he Lord is not slow about his promise, as some think of slowness, but is patient with you, not wanting any to perish, but all to come to repentance.
Then he is not all-knowing, is he?
He is all-knowing. Some things he definitely has predetermined but for the most part He knows everything as possibilities. It's called Open theism. Greg Boyd is my favorite teacher on this subject. I still have some reservations about this doctrine but more and more I'm see the reality of in the Bible. The story of Abraham and Isaac is just one example of it.
How is it a risk for him?
The risk for God is rejection by his own creation.
We are the ones that end up in hell if it goes wrong.
God sends us there reluctantly with a heavy heart. He keeps reaching out to us to turn from our wicked ways. He has no pleasure in the death of the wicked.
I find the god of the Bible to be somewhat offensive, certainly.
Concerning Old Testament violence, I don't have all the answers or even good answers. I know God from Jesus Christ and sometimes the God in the OT doesn't look a lot like Jesus yet it is the very same God. I don't know how to explain this disconnect I see at times.
I can point you to an author and preacher who seems to have an answer to this subject. His name is Greg Boyd. His book is called
Cross Vision which deals with old testament violence. I haven't started reading my copy of the book yet. You can also listen to him teach on this subject online.
https://whchurch.org/sermon/something-else-is-going-on/ or search his website
https://reknew.org/blog/
I have yet to have a Christian explain to me why I should find Satan offensive, given that the only crime they can point to is opposing Yahweh.
Even in the book of Job you don't find Satan offensive?