They think they are very important and deserve honor and praise from men. Today it is used to describe one who is a physician or medical healer. It is also the name of the highest degree one can attain in education. But it is not a title to be worn by leaders in the church, whether preachers, teachers, elders, etc. But it is wrong to use it as a special title for religious teachers.
Many people confuse the work of pastors with that of preachers or evangelists.
Evangelists are preachers of the Word of God. Be ready in season and out of season. But evangelists may serve just one congregation in preaching the gospel or they may be sent out to establish new congregations. They simply describe different workers in the church. It is sinful for a Christian to exalt himself above his fellow Christians by wearing special clothing to set himself apart from them.