Simple justice demands that while Christ suffers for my guilt, Satan must also be punished as the instigator of sin.
That is why, on the Day of Atonement, two goats were necessary. One was "for the Lord" (Lev. 16:7) to provide the atonement through the shedding of his blood; the other was "for Azazel" (Lev. 16:8). These two were, in the text, placed in antithesis. One typified our Lord and Saviour Jesus Christ, who was slain as our substitute and vicariously bore our sins, with all the guilt and punishment entailed. Thus He made complete atonement for our sins. The other goat, we believe, stood for Satan, who is eventually to have rolled back upon his own head, not only his own sins, but the responsibility for all the sins he has caused others to commit.
Now two vital points involved are to be particularly noted: (1) that the transaction with the live goat (or Azazel) took place after the atonement for the sins of the people had been accomplished, and the reconciliation completed; and (2) that the live goat was not slain, and did not provide any propitiation or make any vicarious atonement. And without the shedding of blood there is no remission (Heb. 9:22). None of the blood of the live goat was shed, or poured out in propitiation, and none was taken into the sanctuary and sprinkled before the Lord, or placed on the horns of the altar.
Satan makes no atonement for our sins. But Satan will ultimately have to bear the retributive punishment for his responsibility in the sins of all men, both righteous and wicked.