BROTHER, a male relative born of the same, or at least one of one’s parents. Two Heb. terms are so tr. 1. אָח֮, H278, and common to most Sem. languages. This word appears over 300 times in the OT and in every book except five. It represents the second rank of intimate relationships in the system of Sem. social relations (see Family). The concept is used first and foremost for male siblings. Used initially of Cain and Abel, sons of the same parents (Gen 4:8, et al.), of brothers by one father but different mothers (37:4, et al.), of cousins under certains conditions of consanguinity (16:12, et al.), of other close blood relations (9:25, et al.) and of companions by choice such as lovers. In ancient Near Eastern texts such as the Amarna and Mari letters as well as letters from other locations, family designations are used to indicate the superior or inferior status of the person addressed, thus “father” to a greater, “brother” to an equal and “son” to an inferior without any connotation of blood relationship. Such forms of address using “brother” are found in Genesis 29:4; Numbers 20:14; and elsewhere, and in many funeral laments and dirges (Jer 22:18, et al.). The word appears also as a compound or component of names both Heb. e.g. Ahab,=brother plus father, “quite the father,” and gentile, Sennacherib,=“The moon god has substituted my brothers for me,” and also in names bearing divine titles, Ahijah,=“brother of Jehovah.” On one occasion the common Heb. term for friend, “companion,” רֵעַ֮, H8276, is tr. as “brother” by KJV (Deut 24:10), RSV correctly reads, “neighbor.”

In the NT the common Gr. word for “brother” is used exclusively, ἀδελφός, G81, which appears over 100 times, the most frequent being in Matthew’s gospel. Although a broader definition of the word is apparent in the NT, possibly due to the broader definition of the Gr. word, yet the responsibilities of brotherhood are much the same as those of the OT. The often sought notion of the innate brotherhood of all mankind is not supported by the usage of the term in the NT. The teaching of Matthew 12:50, “For whoever does the will of my Father in heaven is my brother,” is the primary definition of the term in the other references where it is used. In the epistles it is a straightforward substitute for fellow Christians (Eph 6:2, et al.). The responsibility for mutual love, compassion and respect within the Christian community are stipulated in 1 John consistently in terms of “brother” to “brother.”