Boyd’s Bible Dictionary:

In Hebrew sense, any descendant however remote
(Gen. 29:5; 2 Sam. 19:24). Applied also to pupils, adopted persons, those of kindred faith (Gen. 48:5; 1 Sam. 3:6; Acts 13:6).

Concise Bible Dictionary:

Besides the application of this term to natural generation, it is used metaphorically in scripture. The appellation “son” implies “likeness.” The term is employed thus to mark moral likeness, as of a son to a father, so “a son of Belial” (1 Sam. 25:17); “thou son (υἱός) of the devil” (Acts 13:10); “sons of disobedience” (Eph. 5:6; Col. 3:6): also “sons of light” and “sons of day” (1 Thess. 5:5). It is also used to signify physical likeness: strong men are “sons of strength” (2 Kings 2:16, margin).
The idea of sonship differs somewhat in the case of Christians from that of being “children.” The thought of “children” is more of a generation which is of God. “Now are we the children of God” (1 John 3:2). “Sons” expresses the height of God’s calling, and properly refers to heaven and glory. It implies intelligently entering into the purpose of God. God is bringing many sons to glory (Heb. 2:10). Christians are represented as being both children and sons of God. The distinction between these two words is not always clearly maintained in the AV. In Rom. 9:26-27; 2 Cor. 3:7, 13; Gal. 3:7, 26; Eph. 2:2; Eph. 5:6; Col. 3:6; 1 Thess. 5:5; Heb. 11:22; Heb. 12:5; Rev. 2:14; Rev. 7:4; Rev. 12:5; Rev. 21:12 (and often in the Gospels and the Acts) “sons” (υἱός) should be read instead of “children.” On the other hand, in John 1:12; 1 Cor. 4:14,17; Phil. 2:15,22; 1 Tim. 1:2,18; 2 Tim. 1:2; 2 Tim. 2:1; Titus 1:4; Philem. 1:10; 1 John 3:1-2, “children” (τέκνον) should be read instead of “sons.” Both words are employed in the Epistles of Paul, but “τέκνον” only, as regards believers, in the writings of John, except Revelation 21:7. See SΟNS OF GOD.