Millennium means 1,000. In the Bible, the millennium refers to the 1,000 year reign of Christ on earth. Revelation 20:1-3 (italics added), “And I saw an angel (Jesus) come down from heaven, having the key of the bottomless pit and a great chain in his hand. And he laid hold on the dragon, that old serpent, which is the Devil, and Satan, and bound him a thousand years, And cast him into the bottomless pit, and shut him up, and set a seal upon him, that he should deceive the nations no more…”
As Revelation 20 teaches, during the millennium, Christ will bind Satan and destroy the evil systems of earth. When the evil systems are destroyed, the lies and deceptions will end. Christ will teach mankind truth, justice, love, and forgiveness. Both Isaiah and Jeremiah agree with this. “My soul yearns for you…For when your judgments are in the earth, the inhabitants of the world learn righteousness.” Isaiah 26:9 (ESV) “They shall not hurt nor destroy in all my holy mountain (kingdom): for the earth shall be full of the knowledge of the LORD, as the waters cover the sea,” Isaiah 11:9. “No longer will one teach his neighbor or his brother, saying, ‘Know the LORD,’ for they will all know me, from the least to the greatest of them” — this is the LORD’s declaration. “For I will forgive their iniquity and never again remember their sin.” Jeremiah 31:34 (CSB).
What else will happen during Christ’s millennial reign? All mankind will be resurrected (John 5:28,29) and people will be reunited with their loved ones. Everyone’s health will be restored back to perfection. Isaiah 35:5-7 (NET), “Then blind eyes will open, deaf ears will hear. Then the lame will leap like a deer, the mute tongue will shout for joy; for water will flow in the desert, streams in the wilderness…”
Even the earth will be healed. Ezekiel 34:26,27, “I will cause the shower to come down in his season; there shall be showers of blessing. And the tree of the field shall yield her fruit, and the earth shall yield her increase, and they shall be safe in their land, and shall know that I am the LORD…”
The wonderful Millennium is the kingdom for which Jesus taught us to pray, “Thy kingdom come, thy will be done in earth as it is in heaven.” Matthew 6:10.