While visiting Jerusalem's temple a few days before his crucifixion, Jesus seized on the opportunity to educate the multitudes. After warning the crowd (and his disciples) about the hypocrisy of Jewish leaders, he further warns them regarding religious titles vainly enjoyed by such leaders.
Christ's teaching regarding religious titles is clear and to the point. He states, ". . . they (Jewish leaders) love the first place at the suppers . . . And the salutations in the marketplaces, and to be called by men, 'Rabbi, Rabbi.' But you are not to be called Rabbi; for one is your Master . . . Also, do not call anyone on the earth your Father; for one is your Father, Who is in heaven. Neither be called Master; for one is your Master, the Christ (Matthew 23:6 - 10, HBFV throughout).
The Greek word Rhabbi (Strong's Concordance #G4461) in Matthew 23 is translated as "Rabbi" in verse 7. Its literal meaning is "my master" (Strong's) or "my great one" (Thayer's Greek Definitions). Clearly, the use of this religious label is one of the many titles prohibited in Scripture.
The Greek Pater (Strong's #G3962) is where we get the English word "father." Some denominations, like the Catholics, permit the use of this title for its priests. Its use as a recognition of a man's religious position, training or authority is forbidden in the Bible. This includes the blasphemous designation of the head of the Catholic Church as the "most holy father." It is perfectly acceptable, however, to refer to one's male parent as "father."
The word from which we get the English "master" in verses 8 and 10 of Matthew 23 comes from the Greek kathegetes (Strong's #G2519). Its use as a title references someone who is a teacher or guide with the implication that they possess a powerful religious position or office. Jesus, as the God of the Old Testament, claims exclusive use of "master" for himself!
Other religious titles that are unacceptable, based on the spiritual intent of Jesus' teachings in Matthew 23, are "Pope," "Vicar of Christ" and others used primarily by the Catholics. Such designations are utilized to denote a person they believe is the highest-ranking spiritual authority on earth (1913 Catholic Encyclopedia). The word "vicar" means a person who acts in place of another or as their substitute (dictionary.com).
Like "most holy father," the title of "Pope" is not only wrong but also blasphemous. This is because such appellations convey the belief that a person has been given divine authority and power over Christians. This is against what the Bible teaches, which states no man is to rule over the faith of another (see 1Peter 5:2 - 3).
Christ never gave any human being the absolute power to dictate doctrine for all other believers and rule over their faith. Even the apostle Peter, whom Catholics consider the first Pope, never claimed such authority for himself. He, instead, referred to himself as "a fellow elder" (1Peter 5:1), one of many mature Christian believers who served in the church.
God does not want those who believe in him to use titles that falsely try to convey someone has a greater spiritual "rank" or authority than others. The apostle Paul taught that even he did not claim authority over anyone's faith, but rather saw himself as someone who helped increase a person's joy in God (2Corinthians 1:24).
How are Christians to refer to one another? Two acceptable New Testament references to other believers, including those more mature in the faith, are "brother" (Romans 14:10, 1Corinthians 16:12, Ephesians 6:21, etc.) and "sister" (Romans 16:1, 1Corinthians 7:15, James 2:15, etc.).
Some have wondered whether the abbreviation "Mr.," which originated in the mid-1500s as a shortened form of the word "master," is acceptable to use. In modern times, this term is not used as a religious title but instead is usually used as a generic courtesy reference to an adult male. It is generally acceptable to use.