The word “Millennium” is not found in the Bible, but it refers to the “Thousand” years as mentioned in Rev. 20: 1 - 6 at least six times.
People often ask the question, “What is going to happen after the Church is caught up? The Word of God is our only guide, and from it we glean all that is necessary for our enlightenment. We will endeavour to briefly fix our attention on what will take place and then the reader can persue this study for themselves.
Immediately after the Rapture, i.e.., the home coming of the Church or the Bride of Christ for the marriage supper of the Lamb, as we can see in Rev. 19: 7 - 10, after which there will be a period of seven years such as the world has never known, ending with the battle of Armageddon. Then Christ will return to earth with power and great glory, to set up His Millennium Kingdom, and to reign as King of kings and Lord of lords.
The first half of the seven years will be almost an Armistice, and the coming Anti-Christ will confirm the covenant with the returned Jews for one week or for this period of seven years, but in the middle of the period he will break his covenant and then will begin the time spoken of in scripture as “the time of Jacob’s trouble.” Note Daniel 12:1

When our Lord returns to earth after the marriage supper of the lamb in heaven, He will find all nations gathered around Jerusalem, as stated in Zec. 14:2 and He will destroy them.
The Millennium will be for a period of 1000 years, and we are given a glimpse of His reign in Isa. 2:2 - 5.

”Behold, the days come, saith the LORD, that I will raise unto David a righteous Branch, and a King shall reign and prosper, and shall execute judgement and justice in the earth............ his name whereby he shall be called, THE LORD OUR RIGHTEOUSNESS. Jer. 23: 5 - 6.

During our Lord’s reign of peace, blessing and justice, Satan will be a prisoner in the bottomless pit, and under control, so that he will no longer “roam like a roaring lion seeking whom he may devour.”

His confinement will make such a rule, as set forth in Isa. chs. 11 & 12 possible - when

“The earth will be full of the knowledge of the Lord, as the waters cover the sea.”

The Jews will come into their own during this reign, and will play a prominent role in the kingdom as missionaries. What people are better fitted for such a programme? The Jews speak every language under the sun, so there will be no language difficulties. We read in Zec. 8:13 “And it shall come to pass, that as ye were a curse among the heathen, O house of Judah, and house of Israel; so will I save you, and ye shall be a blessing: fear not, but let your hands be strong.”

After the culmination of the 1000 years we read, that Satan is to be loosed for a short period as though God would show the world even after 1000 years of Christ rule of peace, just how evil man is. Satan goes forth and in his final attempt to over throw our Lord’s rule he collects an army and marches against Jerusalem. This army is to be consumed by fire from heaven and the leader-Satan will be cast into the lake of fire to join the other two of the trinity of evil, ie., the beast and the false prophet, where all three shall be tormented for ever and ever. Rev. 20: 7 - 10

The saddest scene of all is the Judgement of the Great White Throne, when ALL whose names are not found written in the Lamb’s Book of Life will be cast into the lake of fire to join him whom they have served so faithfully here and then when it is forever too late, they will realise the truth of the words, “whatsoever a man soweth, that shall he also reap.” Gal. 6:7 - 8.

“Too late too late will be the cry Jesus of Nazareth has passed by”

“We must remind our hearts that “now is the accepted time, now is the day of salvation.”

Tomorrow maybe too late! We must prepare to meet our God for the days that we are speaking of in these words are on our door step.