The harvest of the kingdom is in the book of Revelation. In principle, whatever is revealed in the first pages of a book is the main point of that book. For example, Genesis begins, "In the beginning God created the heaven and the earth." Surely Genesis is a book which reveals God's creation. What is revealed in the first few verses of the book of Revelation? In 1:9 John told us that he was our brother and joint partaker in the tribulation and kingdom and endurance in Jesus. He is our companion in the kingdom! The Lord's intention in this book is to open up the matter of the kingdom to all the saints. Yet in the first few chapters of Revelation, the lampstands, the churches, are revealed, not the kingdom. This means that, practically speaking, the churches are the kingdom. The proper church life is the reality of the kingdom. The churches are not just for the churches, but for the kingdom. In Revelation John did not say that he was one of the members of the Body of Christ, but that he was our companion in the tribulation and kingdom and endurance in Jesus. Tribulation is needed for the kingdom, and endurance is needed for the tribulation. If we would enter into the kingdom we must suffer. To bear the suffering we need a certain amount of endurance. And this is not our endurance, but the endurance of Jesus. Thus, the book of Revelation opens with the kingdom.
In Revelation 12 there is the birth of the man-child. The man-child signifies the overcomers who have the authority to rule over the nations. This man-child will be raptured to the throne of God in the heavens. When the man-child is raptured to the throne there will be a great battle in the heavens against Satan, and Satan will be cast down to the earth. Today the enemy, Satan, is still in the heavens, but once the overcomers arrive there, he will have no place. He will be cast down. Once he is cast down, a loud voice will declare, "Now is come the salvation and the power and the kingdom of our God and the authority of His Christ, for the accuser of our brothers has been cast out, who accuses them before our God day and night" (Rev. 12:10). Thus, Revelation begins with the kingdom in chapter one and also declares the coming of the kingdom in chapter twelve. This indicates that Revelation is a book on the kingdom. Matthew contains the seed of the kingdom, the Epistles contain the growth of the seed, and Revelation contains the harvest of the seed of the kingdom.
What is the harvest of the kingdom? The first aspect of the harvest of the kingdom is the seven lampstands, and the ultimate harvest of the kingdom will be the holy city, New Jerusalem. The New Jerusalem is simply the harvest of the kingdom to the uttermost. In the New Jerusalem the kingdom will be fully manifested. Even the millennium will not be the ultimate manifestation of the kingdom. But the New Jerusalem will be the ultimate consummation and fullest manifestation of the kingdom.
The first few chapters of Revelation show us our participation in the kingdom. God's intention for the church is to have the kingdom, and for this all His believers must be matured to the extent that they can live in the reality of the kingdom and bring in the manifestation of the kingdom. We have seen previously that the manifestation of the kingdom will simply be the maturity and the ultimate growth of the kingdom life. When we live in the reality of the kingdom in its ultimate state, that will be the manifestation of the kingdom. God's purpose is to have the church which can bring in His kingdom. Many Christians have never seen God's purpose and God's goal. They think that God's purpose in the redemption of Christ is to enable people to go to heaven. We all must come back to the pure Word of the Bible to see that the redemption of Christ is to bring in the kingdom. The church in a normal way is simply the reality of the kingdom, and this reality will consummate in the manifestation of the kingdom.
Unfortunately, many real Christians have not seen this view and are short of this experience. Most have fallen below the standard of the normal life. Therefore, in the last book of the New Testament, Revelation, the Lord Jesus sounded forth a call, not to the unbelievers, but to the believers. Every believer has been called once by the Lord. But in Revelation 2 and 3 the Lord Jesus sent forth a second calling to the believers, a calling to be overcomers. We all have been called to believe, and we all have been called into the church life. But many are still short of the Lord's purpose and not up to the normal level which is adequate to bring in the manifestation of the kingdom. Because so many are below the normal level, there is no possibility for them to grow in life. Although the life of the Lord Jesus is within the believers, it has no possibility to grow because they are below the normal level. Because of this, the Lord Jesus issued a call to the overcomers.