Calling another "brother" is a practice that often is taken for granted and done without much thought. The word can be made into a sort of unofficial title. A man who is called on to lead prayer in the assembly is called "Brother so-and-so" and after services are ended he is just "plain Joe." When the preacher for a congregation is introduced to a stranger, in order to identify the man as a preacher, he is called, "Brother so-and-so." Otherwise, he also later becomes just plain old "so and so." It is good to consider what is implied when you call someone, "brother."
It may be that you are referring to your own family when you call someone brother. The word means, "born to the same parents." It is used this way in the New Testament. Of those children born to the parents, Joseph and Mary, it is said they were the "brethren" of our Lord (Luke 8:20-21; John 2:12; 7:3-5). It is evident that Jesus had more family than His mother and father. Actually He had the same mother but not the same father, for Joseph was His father, only in a technical and legal sense. He was simply the husband of Mary; Mary became pregnant with Christ miraculously and not by Joseph. She and Joseph had other children called brethren of Christ.
In the New Testament times when someone was called "brother" it often meant a national kinship. Ananias called Saul, "Brother Saul" before Saul became a Christian and it is evident that they were not born of the same parents. They were brothers in a national sense, inasmuch as both of them were Jews. More than that could not be said. The term was applied sometimes to a "neighbor" (Matt. 7:3) but the most significant and frequent use of it in the New Testament applies to the family relationship in Christ, the church.
You may call someone a brother and by this imply that the individual is a Christian, a member of the family of God, the church of Christ. This is, by far, the most extensive use of the term in the New Testament. Anyone can take a concordance and run the references on "brother," "brethren," and "brotherhood" and see how it applies only to those in the family of God. If you call someone a brother, you imply that such a person has been born again (John 3:5) and is God's child (Gal. 3:26-27). You also imply that they are members of the New Testament church. Paul addressed the church at Colossae as "the saints and faithful brethren" (Col. 1:1). Everett F. Harrison wrote, "It is clear from the Book of Acts and from the Epistles that 'brethren' was the common mode of designation for fellow believers.' (Baker's Dictionary of Theology, page 106).
If you call someone a brother, and that person is not a Christian, a member of the church or a child of God, you have misled that individual and others into thinking that you believe he is saved and is God's child. However, if you know that individual has never obeyed the gospel of Christ, and has no intention of being a member of God's only family, to call such a one a brother is wrong. Be careful, when you call someone a "brother" to be sure you do not imply more than God would. We may call some our brethren who are not God's children and in so doing take more authority on ourselves than God ever allowed anyone. He and He alone has the right to identify people as His children, and God has no children outside of His family.
The means of getting into the family are simple: Faith to become a child of God (Gal. 3:26) and obedience, including repentance and baptism (vs. 27) are the requirements for membership in God's family. One is by this procedure, "born again." Then to remain in the family and remain a brother in Christ, that one must be faithful, even unto death (Rev. 2:10).
- Searching the Scriptures, Sept. 1982