When we share the preaching, we widen the witness. The whole counsel of God is unlikely to be heard by the whole people of God unless they hear from various voices for God.
How often should others be invited to preach?
Often enough to recognize the abilities of staff colleagues. Inviting staff colleagues to preach acknowledges that they bring gifts, training, and a fresh perspective in the ministry of the word. They will invariably reach some folks who may not readily connect with the regular preacher. Having them preach gives visibility to their current ministries and prepares them for future ministries.
Often enough to develop the gifts of church members. Many Protestant churches recognize the “priesthood of all believers”—I wonder if we might not also benefit from the “preacherhood of all believers.” A full-length sermon isn’t the only way to bear witness to the Word. Invite those who are going to read Scripture aloud to introduce the reading with four or five sentences of personal reflection. Readings can come from a lectionary or be passages selected by the members themselves.
Often enough to remember the church beyond our church. It widens our witness when we intentionally bring in voices from outside our own sanctuary (or auditorium) walls. Hearing from other ministers in the local community and from abroad reminds us that God’s church is bigger than our own congregation.
Often enough to remind those who preach regularly that they are pastors as well as preachers. Releasing the preaching for a week frees up time which would normally be devoted to sermon preparation. That time can be spent profitably on other pastoral tasks—especially visitation. Getting the regular preacher out of the study to spend more time in homes and hospital rooms can help to ground the preaching in congregational reality.
There is danger when guest preachers are viewed as understudies who are standing in for the star. Whenever possible, the regular preacher should look to be visibly present when others are preaching. If the senior pastor is away, listening to the recording and commenting later to the congregation on what was said can be an important signal of support.
How often should a senior pastor invite others to preach? Often enough to keep the congregation—and the preacher—from mistaking any single human voice for the voice of God.