After Jesus returns then the devil will be bound and locked up in the Abyss for a thousand years. During this one thousand years there will be peace on Earth under the reign of Jesus Christ. During this period there will be no sin and no evil. Mankind will know how life on Earth was intended to be. But even under God's perfect living conditions; at the end of the thousand years the devil will be released and cause some to rebel against God. But God will send fire down from Heaven to destroy those who have joined Satan. And Satan will be thrown into the Lake of Fire where he will be spending eternity.