Other ministers serve congregations in transition. They help a congregation deal with a myriad of issues after the former pastor has retired or resigned, and they may help them find a new, long-term pastor. There are of course other reasons ministers leave their parish retirement, God's direct calling into other ministries, and so on. But unfortunately by far the most common reason for pastors to leave their churches is because of conflict. Most serious conflicts revolve around power issues the question of who's will is to be done.
Pastors end up serving as CEOs at best, and common employees at worst.
Instead of direction by scripture or the vision of God, the pastor is directed by men and women who are often more interested in maintaining tradition and the status quo than in fulfilling the great commission of Jesus to make disciples above all else. The problem is, most pastors have been called by God and trained to be leaders of congregations. This sets up power struggles with people who are invested in fulfilling their own interests within the church. If your church is experiencing high pastoral turnover, begin by first examining the compensation being offered.