In view of the eternal economy of God, there is the tendency through the whole writing of John to have the church of God issuing in the Body of Christ for the accomplishment of God's eternal economy. Its judicial section qualifies and positions the believers to carry out its organic section by the divine life of the processed and consummated Triune God. But today most Christians are just lingering in its judicial section and are satisfied with it, paying very little attention to its organic section and missing the critical point of the fulfillment of the eternal economy of God. The critical need of the Lord's recovery today is not to be held back by the satisfaction of its judicial section but to press forward to carry out its organic section so that there may be the possibility of accomplishing the eternal economy of God.
John 21 reveals the apostolic ministry in cooperation with Christ's heavenly ministry. After Christ ascended to the heavens, He began His heavenly ministry. In doing this He raised up a group of His followers as His apostles who could fully cooperate with Him. These apostles were commissioned by the ascended Christ to cooperate with Him to carry out God's New Testament economy. What He was doing in the heavens, the apostles did on earth to carry out His heavenly ministry.
The Gospel of John has twenty-one chapters, but it actually ends with chapter twenty. The entire book covers the earthly ministry of Christ, beginning with His incarnation as the Word of God to become a man in the flesh (1:1-14) and ending with His resurrection as the last Adam to become the life-giving Spirit (ch. 20); hence, chapter twenty-one should be an appendix. Although it is correct to say this, it is more intrinsic to say that John 21 is the completion and consummation of the Gospel of John. Without chapter twenty-one, John is not completed. It consummates the entire Gospel of John by showing that Christ's heavenly ministry and the apostles' ministry on the earth cooperate together to carry out God's New Testament economy.
In John 10:10, 11, and 16 the Lord unveiled to the disciples that He was the good Shepherd who came that the sheep might have life abundantly and that He had other sheep (the Gentiles) which He must lead to join with them (the Jewish believers) to be one flock (one church) under one Shepherd.
The Lord's shepherding was firstly in His earthly ministry (Matt. 9:36). The Lord saw the Israelites as sheep harassed by their leaders; they were cast away like sheep not having a shepherd. The Lord as the Shepherd of God's elect prayed, and God told His sent One to appoint twelve apostles that they might take care of the sheep of God (Matt. 10:1-6).