Paul closes his famous section on pastoral ministry in 1 Timothy 4 by saying, “Persist in this, for by so doing you will save both yourself and your hearers.”
How is it that a pastor’s displaying (1 Tim. 4:12,15) and declaring (1 Tim. 4:13) God’s glory works salvation in himself and his hearers? Piper puts it this way: “A pastor’s unflagging moral vigilance over his life and his unwavering theological vigilance over his doctrine are the means of grace appointed by God for his own salvation and the salvation of his people.” In other words, the eternal salvation of a pastor and his people is at stake in the holiness of his life and the truthfulness of his teaching. If a pastor grows lazy in his attention to personal holiness or careless in his teaching the whole counsel of God he will very likely pay with his life and take many of his people with him to hell. See here the gravity of pastoral ministry, it’s a ministry that deals with the things of eternity. The pastor and preacher is God’s ordinary vessel to bring people to faith (Rom. 10:11-14).
When people look at and listen to a faithful pastor, they should see and hear the glory of Christ.