What Matthew 23:9 says, in context
The verse sits inside one of the sharpest speeches in the Gospels. Jesus is speaking “to the multitudes and to his disciples” about the scribes and Pharisees, who do their works “for to be seen of men” and “love the first places at feasts, and the first chairs in the synagogues, and salutations in the market place, and to be called by men, Rabbi” (Matthew 23:1, 5-7). Then He turns to His own followers:
“But be not you called Rabbi. For one is your master; and all you are brethren. And call none your father upon earth; for one is your father, who is in heaven. Neither be ye called masters; for one is your master, Christ. He that is the greatest among you shall be your servant.” Matthew 23:8-11, Douay-Rheims
Read as a ban on a word, the passage would prove too much. It names three titles together, Rabbi, father and master, and the same New Testament calls St. Paul “a doctor of the Gentiles” (1 Timothy 2:7), a teacher by title. What Jesus condemns is the vanity of the men who loved being honored, and any reverence for a man that sets him in the place of God. The note on this verse printed in the Douay-Rheims itself (Bishop Challoner’s) gives the traditional Catholic reading: our Father in heaven is “incomparably more to be regarded, than any father upon earth,” and the verse “does not hinder” due respect “both for our parents and spiritual fathers.” The passage then gives the rule for every man who bears a title: “He that is the greatest among you shall be your servant” (Matthew 23:11).
St. Paul called himself a father
The clearest answer comes from the Apostle who wrote much of the New Testament. Writing to a church he had founded, St. Paul says: “I admonish you as my dearest children. For if you have ten thousand instructors in Christ, yet not many fathers. For in Christ Jesus, by the gospel, I have begotten you” (1 Corinthians 4:14-15). He did not claim to be their Creator or to replace God. He claimed to be the man through whom they received the life of Christ, and he used the word father for it.
He speaks the same way elsewhere. He reminds the Thessalonians that he dealt with them “as a father doth his children” (1 Thessalonians 2:11), and he pleads for Onesimus, Philemon’s servant, as “my son, whom I have begotten in my bands” (Philemon 1:10). This is the fatherhood a Catholic means when he speaks to a priest: a man who brings others to life in Christ and answers for them before God.
The New Testament calls men “father”
The first Christians never treated the word as forbidden. St. Stephen, the first martyr, opens his defense before the council with “Ye men, brethren, and fathers, hear. The God of glory appeared to our father Abraham” (Acts 7:2). St. John addresses the older believers in his flock directly: “I write unto you, fathers, because you have known him, who is from the beginning” (1 John 2:13). St. Paul calls Abraham “the father of us all” (Romans 4:16). And in the same Gospel as Matthew 23, Jesus repeats the commandment “Honour thy father and mother” (Matthew 15:4).
If Matthew 23:9 forbade the word, Stephen, John and Paul would each have broken it, and so would every child who calls his own dad “father.” The verse is about whom a man honors above all, not about a form of address.
What the Catechism teaches about fatherhood
The Catechism grounds the whole question in God Himself. When the Church calls God “Father,” it draws on our experience of human parents, who in a sense first represent God to us; yet God transcends every human father while being the origin and standard of fatherhood, so that “no one is father as God is Father” (CCC 239). Human fatherhood is not a rival to God’s. It comes from His: the Catechism teaches that human fatherhood springs from God’s own, and that this is why parents are owed honor (CCC 2214), pointing to St. Paul’s prayer to “the Father of our Lord Jesus Christ, of whom all paternity in heaven and earth is named” (Ephesians 3:14-15).
That honor reaches beyond the home. The Catechism extends the fourth commandment to teachers, leaders and all who exercise authority over others (CCC 2199). And it describes the priest in the confessional as carrying out the ministry of the Good Shepherd, of the Good Samaritan, and of the father who waits for the prodigal son and welcomes him home (CCC 1465). The Second Vatican Council asks priests to care, “as fathers in Christ,” for “the faithful whom they have begotten by baptism and their teaching” (Lumen Gentium 28). And the Congregation for the Clergy, writing on priestly celibacy, says the priest acquires a “true and real spiritual paternity” of universal dimensions, lived in a particular way toward the community entrusted to him (Directory on the Ministry and Life of Priests, 1994, n. 58).
What a Catholic means by “Father”
When a Catholic says “Father” to a priest, he is not saying the man is God, or that the man stands between him and God in God’s place. He is naming an office: the man who baptizes his children, absolves his sins in Confession, and offers the Mass for his family. The title points past the man to the Father “of whom all paternity in heaven and earth is named.”
It is also a charge on the priest. The same passage that warns against loving titles gives the rule for anyone who holds one: “He that is the greatest among you shall be your servant” (Matthew 23:11). A priest called “Father” is called to live like one. Christians who raise Matthew 23:9 are taking Scripture seriously; the answer is to read the whole chapter, and the rest of the New Testament with it. For how the priesthood itself works in the Church, see Can Catholic Priests Marry? and the seven sacraments.