Clerical Titles! Jesus rebuked the Scribes and Pharisees, condemning the use of titles in Matthew 23:5-12, “But they do all their deeds to be noticed by men; for they broaden their phylacteries and lengthen the tassels of their garments. They love the place of honor at banquets and the chief seats in the synagogues, and respectful greetings in the market places, and being called Rabbi by men. But do not be called Rabbi; for One is your Teacher, and you are all brothers. Do not call anyone on earth your father; for One is your Father, He who is in heaven. Do not be called leaders; for One is your Leader, that is, Christ. But the greatest among you shall be your servant. Whoever exalts himself shall be humbled, and whoever humbles himself shall be exalted.” Thus, robes, collars, and vestments would be a “No” in Jesus’ teaching.
No Authority! Suppose you like to follow the New Testament by command, example, or necessary inference. In that case, you’ll note that there is no authority in the New Testament for referencing a man as a reverend. Do not go beyond what is written, 1 Corinthians 4:6. Furthermore, Christians are warned against self-made religion, Colossians 2:23.
No Example! There’s no example in the New Testament of using religious titles. Paul could have if it were authorized, Philippians 3:4-6. Peter referred to him as “our beloved brother Paul,” 2 Peter 3:15. Peter might have called him Dr. Paul or Rabbi Paul, but he didn’t. There’s grace to be found in humility. If we are Christians, we follow the Lord.