At our Lutheran seminaries, each student studies two years on campus, with an assignment to a local congregation. This provides the student under the supervision of a pastor an opportunity to begin leading worship services, and eventually preaching 1-2 sermons. The third year student is assigned full time to a congregation to experience all areas of pastoral ministry (called vicarage or internship). Then the fourth year student is back on campus to integrate what he learned in the field and hopefully fill some gaps in his theological preparation. Finally graduation and assignment and ordination.
But then what? In the US the average stay for a pastor in a congregation is less than three years. Yet the major conflicts and trails occur in years 3-5. By leaving prior to that the pastor does not experience the trials nor the maturity produced when walking through the trials by ministering faithfully. This is where mentoring can be especially beneficial. By mentoring a new pastor the first three years, this provides a foundation for the pastor to address major conflicts without destroying himself or the congregation. Even better he provides a more mature ministry to those in most need. Watch for more on the mentoring process.