The prophesied release of Satan after the Millennium teaches us significant lessons. God says, “For I am God, and there is no other; I am God, and there is none like Me, declaring the end from the beginning, and from ancient times things that are not yet done” (Isaiah 46:9-10). What Satan does after he is released is history written in advance. His deceptions and warmongering are the future, recorded thousands of years before they happen.
This fact is remarkable to consider. Mankind desires to know the future; we look to news analyses and weather forecasts to glimpse an idea of what lies ahead so we can respond appropriately. We use such indicators to prepare for the future or perhaps to work to change the course of events.
What is astounding is that the Adversary also knows the Scriptures, and he sees his future written in advance. This reality provides vivid testimony of Satan's nature—that he simply will not change, even knowing how disastrous the end will be for him. The advance knowledge makes no difference. So, in addition to God giving Satan his freedom so he can commit his final rebellion, a second reason He must release him is to provide us with this final, powerful lesson about the Serpent's nature.
When God releases Satan, the Deceiver does what he has always done. Even after a thousand years of stasis, his nature remains unchanged. After a millennium of reflecting on his plight, calculating his ideal course of action, and contemplating his spiritual navel, as it were, he reaches the conclusion he started with: He knows better.
Maybe he will not be aware of the peace and prosperity as it blooms outside the pit, but when he is released, he will be able to see that goodness and abundance with his own eyes. Yet even with all the years of mankind under Christ, living the best that people can live, and all the good humanity will produce in cooperation with God, Satan will emerge, discount the evidence, and continue to act in the way that seems best to him, even though it destroys the lives of others.
Isaiah 14 reveals this attitude when it speaks of Helel ascending, exalting his throne, and trying to become the Most High. His image of self-perfection is written in stone. In his heart, he is convinced that he deserves more and better than God gave him.