After 1000 years in solitary confinement the Lord will let Satan, the “snake” of Genesis 3, back in the garden (so to speak) to offer the human race independence from God in order to reveal their hearts.
We learn from the book of Job that Satan plays an important role in God’s plans for mankind. Nothing makes that clearer then the devil’s release from prison at the end of the Millennial Kingdom. The purpose of his release is to “deceive the nations” (Rev. 20:8) one final time.
During the Kingdom Age, earth is filled with righteousness and there is great prosperity. There have been several generations over the 1000 years. The curse is lifted and man’s lifespan is quite long. There is love, righteousness, joy, and peace. There are no demons harassing anybody.
There is no pornography, there is no abortion, there is no perversion. There is nothing like that in the earth. Then Satan is let back into the garden so to speak. What happens is revealing! Millions of unsaved people born during the Millennial Kingdom choose to follow Satan just like Adam and Eve followed the snake.
There are some important reasons why this happens.
One reason is Satan has not been rehabilitated. You would think after 1000 years in prison he would get humble. He is not. He is more angry than ever.
Another reason is that the demons also become more angry, not more humble. They are not rehabilitated. When given the opportunity, they attack again.
God allows this scenario to be played out to reveal the wickedness of man’s heart and to leave man without excuse (Rom. 1:20). There are people who are saying, “If I only had better circumstances, I would not have sinned like Adam did.” The Lord says, Watch this. I am going to show you. I am going to make the glorious environment of Eden across the whole earth one final time to give man a fresh opportunity.
Then I will let the snake back in the garden like I did with Adam. What happens? Multitudes will choose the snake like great-grandpa Adam did because man loves sin.
Even though Christ dwells on earth in all His millennial glory and man sees the glories of redemption, the majority of mankind, at the end of the Millennium, still choose sin instead of the Savior.
This is the final lesson God wants to leave with mankind for all eternity. Given the best opportunity and perfect environment to surrender to Jesus Christ, man chose the wages of sin.