Jesus said the kingdom had arrived when he was here the first time, but the Kingdom of God will not arrive in its fullness until God descends with the new Jerusalem. Some people confuse the first millennium rule of Jesus and his saints, with that heavenly utopia. Restrained in a pit, Satan’s influence is removed, however mortal people living on the earth will still have to overcome their own rebellious human nature.
Luke 11:20 Living Bible
20 But if I am casting out demons because of power from God, it proves that the Kingdom of God has arrived.
Revelation 21:1-4 New Life Version
1 Then I saw a new heaven and a new earth. The first heaven and the first earth had passed away. There was no more sea. 2 I saw the Holy City, the new Jerusalem. It was coming down out of heaven from God. It was made ready like a bride is made ready for her husband. 3 I heard a loud voice coming from heaven. It said, “See! God’s home is with men. He will live with them. They will be His people. God Himself will be with them. He will be their God. 4 God will take away all their tears. There will be no more death or sorrow or crying or pain. All the old things have passed away.”
Zechariah 14:16-18 International Children’s Bible
16 Some of the people who came to fight Jerusalem will be left alive. They will come back to Jerusalem year after year. They will come to worship the King, the Lord of heaven’s armies. They will celebrate the Feast of Shelters. 17 Some people from the nations might not go to Jerusalem. They might not worship the King, the Lord of heaven’s armies. Then rain will not fall on their land. 18 The Egyptians might not go to Jerusalem. They might not celebrate the Feast of Shelters. Then the Lord will send them the same terrible disease the other nations got.
God will allow all people to make a free choice of belief, just as he did with Satan and the angels. Living with God, Satan experienced God’s love, yet the angels and him still rejected God to follow their own rebellious natures. What types of problems do you think mortal people living during the millennium will have to overcome without Satan to influence them? Are sins like pride, envy, lust, in us without the influence of Satan? Do you think people take the love of God for granted now, will they then?