BROTHER
(a) From the same father and the same mother (Gen. 27:6), or from the same father (Gen. 28:2), or from the same mother (Judg. 8:19).
(b) One who has the same ancestry, nephew (e.g., Gen. 14:16), or of the same race or of a nation descended from the same ancestor as the Israelites (Deut. 23:7; Neh. 5:7; Jer. 34:9).
(c) Ally (Am. 1:9) or coreligionist (Acts 9:17; 1 Cor. 6:6; 2 Cor. 2:12, 13). The plural frequently designates the disciples of Christ (Mt. 23:8; Rom. 1:13). Those who are born again are doubly brothers, and should be treated as such (Acts 15:23; 1 Cor. 16:20).
(d) A man whom one loves as affectionately as one’s own brother or to whom one addresses respectfully with this address (2 Sam. 1:26; 1 Kings 20:32).
(e) No exclusions. all members of the great human brotherhood (Gen. 9:5; Mt. 5:22; 18:35).