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 23:5 - 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." Its use, in a religious sense (as the Catholics do when addressing their priests), is also clearly forbidden in the Bible. 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 comes from the Greek kathegetes (Strong's #G2519). Its use as a title in Matthew 5:10 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 and man's Messiah, claims exclusive use of reference for himself.
Other titles that are unacceptable, based on the spiritual intent of Jesus' teachings in Matthew 23, are "Pope," "Vicar of Christ" and others used by the Catholics. Such designations are used by them to denote the 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).
Such religious appellations like "Pope" are not only wrong but also blasphemous, since they claim divine authority and power over Christians that was never given. Christ NEVER gave any human being the absolute power to dictate doctrine and rule over the faith of his people. Even the apostle Peter, whom Catholics consider the first Pope, NEVER claimed such titles 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.
The Bible teaches against using titles, in a religious context, that are meant to convey one person's spiritual "rank" or authority over 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). 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" (dictionary.com), 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.