God has given us pastor/teachers "to equip the saints for the work of ministry, for building up the body of Christ" (Ephesians 4:11-12). The Greek word in the Bible for "pastor" actually means "shepherd" because pastors are called by God to care for the people of God in the same way that a shepherd cares for his sheep (1 Peter 5:2-3). Other words in the Bible that are used to describe the Office of Pastor are "elder/presbyter" (Acts 20:17; 1 Peter 5:1; Titus 1:5) and "overseer/bishop" (Acts 20:28; 1 Timothy 3:1-2; Titus 1:7).
Jesus the Good, Great, Chief Shepherd
We like to say Jesus is our "Senior Pastor" because this is how the Bible describes Him. He is referred to as both the "Good Shepherd" (John 10:14-16), the "Great Shepherd" (Hebrews 13:20-21), and the "Chief Shepherd" (1 Peter 5:4). Jesus tells us, "I lay down my life for the sheep" (John 10:15). This is what Jesus meant when He said, "Truly, truly, I say to you, I am the door of the sheep… If anyone enters by me, he will be saved" (John 10:7-9). Shepherds in the Middle East lay down in the doorway of the sheep-pen to protect their sheep and keep them safe. It's like Jesus is saying, "You want [to be] my sheep? Over my dead body!"
Commission = Go Mission
With the following words Jesus gave the Great Commission to His first disciples, right before He went to the right hand of the Father. This is where we find the "Prime Directive" and calling for every pastor: to make disciples by baptizing, teaching, and proclaiming the Good News of Jesus. We like to call this our "Go Mission."
"Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you." (Matthew 28:19-20)
"Go into all the world and proclaim the gospel to the whole creation. Whoever believes and is baptized will be saved, but whoever does not believe will be condemned." (Mark 16:15-16)
Qualifications
This is a trustworthy saying: "If anyone aspires to the office of overseer, he desires a noble task" (1 Timothy 3:1). This "noble task" has clearly defined qualifications for the men of God who will "shepherd the flock of God" (1 Peter 5:2) and they are found in Titus 1:5-9 and 1 Timothy 3:1-7. God inspired the Apostle Paul to speak these words to every pastor: "Pay careful attention to yourselves and to all the flock, in which the Holy Spirit has made you overseers, to care for the church of God, which he obtained with his own blood" (Acts 20:28).
See also: Biblical Qualifications of a Pastor