The New Testament model for church leadership shows each local congregation being led, whenever possible, by a group of men who have demonstrated spiritual leadership abilities. Their lives of Christian service have earned them the esteem of the congregation, and they have shown that they have the qualities required by Scripture for church overseers (1 Timothy 3:1-7 & Titus 1:5-9).
They are called elders, because they are respected as men of spiritual maturity. They are called overseers, because they are entrusted with the spiritual oversight of the congregation. They are called shepherds, because they feed and protect the spiritual flock entrusted to their care (Acts 20:17, 28; 1 Peter 5:1-3).