God allows free will. He created life. Life chooses to do evil on occasion. Lucifer's point is moot. What he was really trying to do was usurp God's throne with a third of the legion of angels in Heaven. Sorry I don't know computer or tech stuff as well as you do so this won't be as elegant. I'll continue regardless. The assertion that "being all powerful and all knowing at the same time is impossible" is incorrect and, when Lucifer proclaimed this, it wasn't merely an ostentatious bid to "outwit" God as though you were doing this in class with another individual. Knowing full well that existence as we know it hinges on God's existence, he tried to "Ctrl Z" God (as God obviously proclaimed "Don't worry friends, I'm all-knowing and all powerful and, best of all, I can't lie!"), so he could take up the throne in the ensuing vacuum of power and utter chaos.
Basically, the one you're defending created the very evil he is accusing God of being the foundation of.
It's really no different than a lawyer saying it is solely the fault of the parents that their child turned out to be a serial necrophiliac murderer and, by virtue of this, he should receive an "insanity" plead (when the individual we appeal to is obviously very conscious of himself and his actions) or, worse yet, be found not guilty. Worse yet, in this scenario, the parents of said child were actually the kindest parents in the world who gave him a wonderful upbringing and a very emotionally happy, stable and loving childhood.
If I know that you are going to choose the salad and not the soup on January 12, 2023, then that does not mean you are unable to choose between the salad and the soup. You are free to select either one and enjoy at a fair price. You are also free to choose whether you would like vinaigrette or ranch. If God tells somebody when they are going to die before they die, He has already taken into account the actions that will be taken after they receive this information. They had the ability to choose during that time period as well! The same applies to choosing between good and evil too.
Anyways, God saves every single good person in the end. He is guilty of nothing. He saves them by preventing Lucifer from mutilating their soul after they die with lemarchand's box's decompilation and transposition abilities. If you're unaware, basically, what happens, is your soul is ripped apart by hooks attached to chains (this is the decompiling) and then you are "recombined" or reconfigured into Satan's scripting language.
I'd also like to point out that Lucifer is gone. Lucifer went away. Lucifer died. There is no such thing as Lucifer any more. Evil corrupted the angel and turned him into Satan.
Satan is just going to be killed. There won't be any sort of metaphysical detachment with green matrix rain. Also, he has retained all his superuser privileges. As a matter of fact, he is spamming Earth every second of every day with attempts at doing unimaginably painful things to the human race along with all of his servants. Anything that he or the rest of the lot does is with God's permission. Anyways, in the end, it'll be him, in the flesh, along with death itself, every cenobite and Hell itself as well, burning alive forever. Usually they're masochistic and enjoy this sort of stuff, so they said, "Oh, we are going to love this! We'll get so powerful from the pain!" but God has made it clear, "You are not and will not. It is absolute, inescapable inundation."
It has been promised by Him.
The targets have been identified. The function will be released. The targets will be completely silenced.