ἀδελφός

(οῦ, ὁ (from ἆ copulative and δελφύς, from the same womb; cf. ἀγάστωρ) (from Homer down);
1. a brother (whether born of the same two parents, or only of the same father or the same mother): Mt 1:2; Mt 4:18, and often. That 'the brethren of Jesus,' Mt 12:46, Mt 12:47 (but WH only in marginal reading); f; Mk 6:3 (in the last two passages also sisters); Lk 8:19; Jn 2:12; Jn 7:3; Acts 1:14; Gal 1:19; 1 Cor 9:5, are neither sons of Joseph by a wife married before Mary (which is the account in the Apocryphal Gospels (cf. Thilo, Cod. Apocr. N. T. i. 362f)), nor cousins, the children of Alphaeus or Cleophas (i. e. Clopas) and Mary a sister of the mother of Jesus (the current opinion among the doctors of the church since Jerome and Augustine (cf. Lightfoot's Commentary on Galatians, diss. ii.)), according to that use of language by which ἀδελφός like the Hebrew אָח denotes any blood-relation or kinsman (Gen 14:16; 1 Sam 20:29; 2 Kgs 10:13; 1 Chr 23:2, etc.), but own brothers, born after Jesus, is clear principally from Mt 1:25 (only in R G); Lk 2:7 — where, had Mary borne no other children after Jesus, instead of υἱόν πρωτότοκον, the expression υἱόν μονογενῆ would have been used, as well as from Acts 1:14, cf. Jn 7:5, where the Lord's brethren are distinguished from the apostles. See further on this point under Ἰάκωβος, 3. (Cf. B. D. under the word ; Andrews, Life of our Lord, pp. 104-116; Bib. Sacr. for 1864, pp. 855-869; for 1869, pp. 745-758; Laurent, N. T. Studien, pp. 153-193; McClellan, note on Mt 13:55.)
2. according to a Hebrew use of אָח (Ex 2:11; Ex 4:18, etc.), hardly to be met with in secular authors, having the same national ancestor, belonging to the same people, countryman; so the Jews (as the σπέρμα Ἀβραάμ, υἱοί Ἰσραήλ, cf. Acts 13:26; (in Deut 15:3 opposed to ὁ ἀλλότριος, cf. Acts 17:15; Acts 15:12; Philo de septen. § 9 at the beginning)) are called ἀδελφοί: Mt 5:47; Acts 3:22 (Deut 18:15); Acts 7:23; Acts 22:5; Acts 28:15, Acts 28:21; Rom 9:3; in address, Acts 2:29; Acts 3:17; Acts 23:1; Heb 7:5.
3. just as in Lev 19:17 the word אָח is used interchangeably with רֵַעַ (but, as Lev 19:16, Lev 19:18 show, in speaking of Israelites), so in the sayings of Christ, Mt 5:22, Mt 5:24; Mt 7:3ff, ἀδελφός is used for ὁ πλησίον to denote (as appears from Lk 10:29ff) any fellow-man — as having one and the same father with others, viz. God (Heb 2:11), and as descended from the same first ancestor (Acts 17:26); cf. Epictetus diss. 1, 13, 3.
4. a fellow-believer, united to another by the bond of affection; so most frequently of Christians, constituting as it were but a single family: Mt 23:8; Jn 21:23; Acts 6:3 (Lachmann omits); Acts 9:30; ; Gal 1:2; 1 Cor 5:11; Phm 1:14, etc.; in courteous address, Rom 1:13; Rom 7:1; 1 Cor 1:10; 1 Jn 2:7 Rec., and often elsewhere; yet in the phraseology of John it has reference to the new life unto which men are begotten again by the efficiency of a common father, even God: 1 Jn 2:9ff; 1 Jn 3:10, ; etc., cf. 1 Jn 5:1.
5. an associate in employment or office: 1 Cor 1:1; 2 Cor 1:1; 2 Cor 2:13(12); Eph 6:21; Col 1:1.
6. brethren of Christ is used of,
a. his brothers by blood; see 1 above.
b. all men: Mt 25:40 (Lachmann brackets); Heb 2:11f (others refer these examples to d.)
c. apostles: Mt 28:10; Jn 20:17.
d. Christians, as those who are destined to be exalted to the same heavenly δόξα (which see, III. 4 b.) which he enjoys: Rom 8:29.