Colossians 1:16-17 shows us that all things consist of God and Hebrews 1:3 shows us that all things are maintained by his word. His will consists of those benevolent efforts and principles which maintain everything and keep it in order. Outside of his will is a dominion called DEATH, where there are destructive actions and principles that lead to nothing but endless darkness, chaos and sorrow. Satan was cast out into this dominion of death when he rebelled against the will of God and tried to overthrow him (Isaiah 14:12-17).
Satan realized from the first instant he was thrown out into death that he was a goner, so he used his powers to make the dominion of death attractive, which is why destructive urges like adultery, violence, pride, greed, theft, etc, etc, all feel so good at FIRST, but eventually lead to pain and misery, and not just for ourselves, individually, but for each other. (And only an idiot would deny that our world is filled with these destructive principles and that they are ruining us completely). This is why the Bible says that Satan had the power of death in Hebrews 2:14.
It worked. Satan tricked MAN into also entering this dominion of death when he convinced Adam and Eve that they could become like gods by disobeying God (Genesis 2:17 - 3:5). No doubt, Satan let God know immediately afterwards that he couldn't get rid of him and the dominion of death now without getting rid of man also.
But God had a plan for man's redemption. Just as it had taken only one man to ruin everything, it would only take one man to REDEEM everything. This redeemer would be Jesus, of course (Romans 5:19).
To render Satan's power of death null and void, Jesus had to occupy and commandeer death, and then come back from it with us in his hands. He did that on the cross, following Satan (and us) into the dominion of being outside of the will of God, becoming a curse in our place, which is why God looked away from him (Habakkuk 1:13), and why Jesus cried out, "Why hast thou forsaken me?" (Matthew 27:46). People, this was a feat of monumental proportions, and Jesus was not sweating those huge drops of blood (Luke 22:44) from merely dreading the physical pain of the crucifixion.
The important thing is, Jesus had no sin on him whatsoever, so the dominion of death could not hold him:
24. Whom God hath raised up, having loosed the pains of death: because it was not possible that he should be holden of it.
25. For David speaketh concerning him, I foresaw the Lord always before my face, for he is on my right hand, that I should not be moved:
26. Therefore did my heart rejoice, and my tongue was glad; moreover also my flesh shall rest in hope:
27. Because thou wilt not leave my soul in hell, neither wilt thou suffer thine Holy One to see corruption.
Jesus came BACK from the realm of death, BACK from the foreign dominion of being outside of the sight of God, his body restored (just as ours will be) and with the keys of hell and death in his hands...
I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death.
The power of death is now HIS and THAT is how he's able to save us from it...
Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death he might destroy him that had the power of death, that is, the devil;
This is why he can save ANYONE, no matter how bad or how much they've sinned:
Wherefore he is able also to save them to the UTTERMOST that come unto God by him, seeing he ever liveth to make intercession for them.
To sum it up: Satan went outside of the will of God, found out there was only death there, tried to handcuff himself to us by tricking us into going there with him. Jesus occupied and commandeered the whole dominion of being outside of the will of God and turned it over, the power of death is now his, which is why he can save us from it. And this is why Jesus is the only - ONLY - way back to redemption:
Neither is there salvation in any other: for there is none other name under heaven given among men, whereby we must be saved.
So, why didn't Jesus' work on the cross redeem Satan and all of the fallen angels too? Because Jesus wasn't made in the likeness of angels, he was made in the likeness of MAN. He came as a representative of MAN, not the angels.
16. For verily he took not on him the nature of angels; but he took on him the seed of Abraham.
17. Wherefore in all things it behoved him to be made like unto his brethren, that he might be a merciful and faithful high priest in things pertaining to God, to make reconciliation for the sins of the people.
This was why Satan was trying to infiltrate the seed of man with angelic seed (Genesis 6:1-4), so that Jesus couldn't be born purely as man, thus preventing him from being our representative. This contamination was the REAL reason for the flood. Only Noah, his wife, his three sons and their wives - eight people - remained uncontaminated. The Bible shows in Genesis 6:9 that Noah was "perfect in his generations." The root word of generation is 'gene.'
So, yeah, Satan and his angels are up the creek without a paddle (Matthew 25:41), and so is anyone who doesn't allow the blood of Jesus to pull them out out of the dominion of death. Like the Bible says, it's a terrible thing to fall into the hands of the LIVING God (Hebrews 10:31).