The millennial reign of Christ will last for one thousand years. It will occur after His second coming. During this time peace will rule. How will the Holy Spirit function during this period? Will there still be the need for people to be converted?

Those who survived the Great Tribulation and have not believed in Him will be judged by Christ at His second coming before the Millennium begins. When the Millennium begins, all those who enter into it will be believers. Both Jews and Gentiles who have survived the Great Tribulation with faith in Christ will enter this period.

Judgment on Gentiles

Jesus talked about the judgment of the unbelieving Gentiles.

When the Son of Man comes in His glory, and all the holy angels with Him, then He will sit on the throne of His glory. All the nations will be gathered before Him, and He will separate them one from another, as a shepherd divides his sheep from the goats. And He will set the sheep on His right hand, but the goats on the left. Then the King will say to those on His right hand, Come, you blessed of My Father, inherit the kingdom prepared for you from the foundation of the world.'...Then He will also say to those on the left hand, Depart from Me, you cursed, into everlasting fire prepared for the devil and his angels (Mat 25:31-34, 41).

Judgment of the Jews

The prophet Zechariah spoke of the judgment of the Jews:

"And it shall come to pass in all the land," says the LORD, "That two thirds in it shall be cut off and die, but one-third shall be left in it: I will bring the one-third through the fire, will refine them as silver is refined, and test them as gold is tested. They will call upon My name and I will answer them. I will say, 'This is My people'; And each will say, 'The LORD is my God!'" (Zec 13:8-9).

Those that survive these two judgments will enter the millennial period. Therefore all those who begin the Millennium are believers.

Children Will Be Born

However, children will be born during this period, and each of them will need to make a personal decision toward Christ. The Holy Spirit will be working in their lives to bring them into a relationship with God. Yet, despite the Holy Spirit's work, there will be those who reject Christ:

Now when the thousand years have expired, Satan will be released from his prison and will go out to deceive the nations which are in the four corners of the earth, Gog and Magog, to gather them together to battle, whose number is as the sand of the sea. They went up on the breadth of the earth and surrounded the camp of the saints and the beloved city. And fire came down from God out of heaven and devoured them (Rev 20:7-9).

Therefore, we see the need for the Holy Spirit to work during the Millennium in the lives of unbelievers.