Acts 20:28

Watch out for yourselves and for all the flock of which the Holy Spirit has made you overseers, to shepherd the church of God that he obtained with the blood of his own Son.

Paul is charging the Ephesian elders to guard themselves and other believers in Christ Jesus. Paul says that it is the Holy Spirit that has made them overseers, and it is so with our churches today. Each and every pastor and leader in the church has been made an overseer by the Holy Spirit of God. This is not a responsibility that should be taken lightly, and if it is handled irresponsibly, there will be consequences for it. Lives are at stake, and that is the reason for the urgency in Paul's charge. Paul also reminds them, that it is God who makes it possible to build a church at all.