Continuing on with my replies to the comments and questions on the fight I started.
…I could see some mental objections he could raise. Like being in Christ was for holy and blameless existence and that wouldn’t necessitate a Fall.
I suppose that objection could be raised, except that Ephesians 1 says that the plan (or the mystery of his will) didn’t only include holy and blameless existence, but “redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace.” To graciously forgive our trespasses requires trespasses to forgive.
Did Satan sin when he was removed from Heaven?
In Genesis 3, Satan is tempting Eve, so he had already sinned by that time. We are also told the devil “has been sinning from the beginning.” (1 John 3:8 ESV) Some time very early in the history of creation, before the fall, Satan sinned.
Was sin created in eternity past or when Adam fell?
I don’t think sin is a created thing. John Murray says it’s the contradiction of God and that seems to be a pretty good definition to me. If that’s what it is, then sin didn’t exist in creation until Satan opposed God. Sin came into the human race when Adam and Eve disobeyed God’s command concerning the tree.
Please share what you would have done differently.
I’d have stated my answer to the original question differently than I did. Not because the answer was wrong, but because it might have been easier to accept if I’d stated it differently. I think it would have been wiser to start with the reason for my answer and then give my conclusion.
So if I were given the opportunity to start the whole thing over and answer the question of why God put the tree of the knowledge of good and evil in the garden again, I’d start with the centrality of redemption to God’s plan for creation, and then worked back from that to God’s placement of the tree as part of that plan and the tree’s intended role in the fall of humankind.