God's calling is specific. When God calls His servants, He assigns them special ministries to accomplish His purpose and uses various means to prepare each of His servants. In the New Testament we see three striking examples of concrete ministry, which are represented by the three leading apostles - Peter, Paul and John.

In the book “What Should This Man Do?” Watchman Nee, in revealing the central aspects of the ministry of these apostles, shows three major historical emphases that God gave to His people. In Peter's case it is the gospel and winning people for the kingdom of God; in the case of Paul, the building of these people in accordance with the revelation he received about the church as the Body of Christ; in John's case, the return of God's people to God's original purpose, to that which had been lost through the degradation of the church. At the same time, the author clearly shows today's aspects of the application of these three ministries in fulfilling God's plan to build the church.