In the United Methodist Church, we operate with an itinerant system of ministry. This means that pastors are not called by a congregation to serve their church. Rather, pastors are sent by a bishop who oversees their ministry with the assistance of other superintending pastors. When I explain this system to people for the first time, they often respond with surprise that we operate this way. Many might be even more surprised, though, to learn that this method of pastoral appointments is grounded in the practice of the New Testament church.
The first occurrence of a "sent out" ministry comes in Acts 13:1-3. The prophets and teachers in the church at Antioch were instructed by the Holy Spirit to set apart Barnabas and Saul for the work for which the Spirit has called them. These leaders discerned the intention of God's Spirit during a time of fasting and praying. Then they laid hands on Barnabas and Saul and sent them off to the ministry to which the Spirit had called them.
The second occurrence of evidence for a "sent out" or "appointed" ministry comes in Paul's letter to Titus. Paul indicates that he left Titus in Crete to "put in order what remained to be done, and should appoint elders in every town, as I directed you" (1:5). Paul then goes on to list certain qualifications that overseers ought to meet. The point here is that Paul expects Titus to oversee the appointment of pastors in multiple towns and the local churches in them. The choice of the pastor is not here left to the congregation of the local church. Instead, Paul charges Titus with the responsibility to appoint numerous elders in numerous places. Titus has the responsibility to discern who meets the qualifications of an overseer and to place them where he discerns they will be most effective. Paul clearly teaches a hierarchical or top-down approach to elder selection and appointment.
So, why do Methodists practice an itinerant or sent pastoral ministry? Because such a ministry is clearly taught in the New Testament. The United Methodist Bishop who is faithful to his consecration will make every effort to faithfully discern the leading of the Holy Spirit in the appointing of pastors to churches. Admittedly, this does not always happen. There are those who use their authority as a way to maintain power and puff themselves up. However, this does not mean that the appointment process should be abandoned. Rather, all involved, Bishops and pastors, should make themselves available for God's work being sure that pastors are sent according to God's call.