Here is a paragraph in which Horton explains the role of the minister in the congregation and especially as a worship leader and pronouncer of the benediction upon God's people:
A minister is not a master. Yet it is also true that a minister is not a facilitator, coach, or team leader. Ministers do not serve at the pleasure of the people, but at the pleasure of the King. It is not their church or their ministry, but Christ's; and it is in their office, not in their person, that they represent the heavenly authority. Not only in the sermon, but throughout the service, they are God's covenant attorneys. Many Christian liturgies include at some point the Aaronic blessing: "The LORD bless and keep you.... The LORD lift up his countenance upon you and give you peace" (Nu 6:24-26). These words are not mere well-wishing, but are God's act of blessing his people. Ministering as diplomats of Yahweh, the priests actually placed God's benediction on the people. It was a legal, convenantal action, a performative utterance that placed the people under the blessings rather than the curses of the covenant: "So shall they put my name upon the people of Israel, and I will bless them" (v. 27 emphasis added). And in the mouths of ministers of the Word today, it has the same performative nature (p. 892).