Paul's letter to Titus is a glimpse in to building a church in the early stages. Titus is facing those who have some teachings contradictory to Christ, but it also needs to build his support group. Setting up elders means that the pastor won't be alone, he will be partnered with others who can support him. God never sent anyone out as a lone wolf. Jesus sent the apostles out two by two, and we today need one another for support just the same as those in the first century.