Why will there be no sin in the Millennial Kingdom?
The Millennial Kingdom will be free from sin because Satan is locked up during that thousand-year period. With the curse lifted and Christ reigning as King, it becomes a perfect government and the utopia human history has anticipated, with only believers entering.
Les teaches that the last thousand years of human history on the planet will be a time of true glory, with a perfect government under Christ the King. He explains that there will be no sin specifically because Satan is locked up during that period. The curse will be lifted, and everything will revert back as it was in the Garden of Eden, making it the utopia all human history has looked forward to. Les also notes that no unbelievers will go into the Kingdom, only believers. The surviving people of the Tribulation who heard the Gospel from the 144,000 and believed will be ready for the Kingdom, while those who rejected the Gospel will be removed from the scene.