Acts 20:28 28Pay careful attention to yourselves and to all the flock, in which the Holy Spirit has appointed you overseers, to shepherd the church of God, which he obtained with his own blood.
After laying out his motivation in his ministry, Paul moved on in his speech to exhortation. He gave his core charge to the elders of what they must do. Those who came from Ephesus were the leaders and were responsible for the spiritual well-being of the other believers. Verse 28 highlights two entities they were to care for. First, they needed to watch themselves. It was crucial that the leaders maintain a growing relationship and faith in the Lord Jesus. If they began to slip in discipline and devotion in any way, their struggle would affect others and lead to many problems in the church and mission.
Second, they needed to care for the flock, referring to the church of God. Paul drew upon the image of the leader as shepherd or “pastor” of the church. Flock (poimniō) shared the same root as shepherd (used as a verb, poimainein). Their ministry position was to be as overseers (episkopous), a term that means to keep watch over a situation. The word is sometimes translated as “bishop,” which carries with it significant overtones from later church history. Often, later interpretation of a bishop is inserted back onto this and other New Testament passages where the word is used (1 Timothy 3:2; Titus 1:7). At this early stage of church development, the position was likely not formalized but more of a description of the spiritual duties of certain people.
These overseers were designated by the Holy Spirit. Somehow, the church and these persons recognized the Holy Spirit’s leadership and special calling and anointing to be spiritual leaders of the growing movement. Spiritual and character qualities were more important than natural gifting or social position.
The powerful source for obedience to the Holy Spirit’s commission comes at the end of verse 28: God purchased the church by his own blood. The phrase itself is a bit challenging in that God the Father does not have blood as such, but God the Son did. The reference is clearly to the blood Jesus shed on the cross. From a Trinitarian perspective about the unity of Father, Son, and Spirit, there is no problem in what Paul said. By God giving his Son to die for us, God shed his own blood. Another option for this phrase is to interpret the word own (idiou) simply as a pronoun for Jesus, meaning “with the blood of his own [Son].” Whatever the case, it is a clear reference to the atonement and how Jesus gave himself for the church (Ephesians 5:25), purchasing the church from the stronghold of sin and depravity.