What is the system of Church service?

Christ appointed twelve disciples to accompany Him, and to send them to preach and gave them authority to heal the sick and cast out demons (Mark 3:14–15; see Matt. 10:1–4; Luke 6:12–16). Then He appointed seventy others, sending them two by two before His face in every city and every place He was about to go (Luke 10:1). When the twelve were in the upper room, He said to them after His resurrection, “‘Peace to you! As the Father has sent Me, I also send you.’ And when He had said this, He breathed on them, and said to them, ‘Receive the Holy Spirit. If you forgive the sins of any, they are forgiven them; if you retain the sins of any, they are retained.’” (John 20:21–23). And before His ascension to heaven, He gave them this command: “Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all things that I have commanded you; and lo, I am with you always, even to the end of the age” (Matt. 28:19-20), showing that the command and the authority given to the holy apostles remain in the Church forever, even after the apostles pass from this life. The Apostle Paul affirmed that the Lord gave the Church: “And He Himself gave some to be apostles, some prophets, some evangelists, and some pastors and teachers, for the equipping of the saints for the work of ministry, for the edifying of the body of Christ” (Eph. 4:11–12).