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Study Dictionary
Godliness
Godliness [EBD]
the whole of practical piety (1 Tim. 4:8; 2 Pet. 1:6). "It supposes knowledge, veneration, affection, dependence, submission, gratitude, and obedience." In 1 Tim. 3:16 it denotes the substance of revealed religion.
GODLINESS; GODLY [ISBE]
GODLINESS; GODLY - god'-li-nes, god'-li (eusebeia, eusebes, eusebos): In the Old Testament the word rendered "godly" in Ps 4:3; 32:6 (chacidh) is literally, "kind," then "pious" (the Revised Version, margin renders it in the former passage, "one that he favoreth"). Sometimes in both the Old Testament and the New Testament a periphrasis is employed, "of God," "according to God" (e.g. "godly sorrow," 2 Cor 7:10). Godliness, as denoting character and conduct determined by the principle of love or fear of God in the heart, is the summing up of genuine religion. There can be no true religion without it: only a dead "form" (2 Tim 3:5). The term is a favorite one in the Pastoral Epistles. The incarnation is "the mystery of godliness" (1 Tim 3:16).James Orr
Also see definition of "Godliness" in Word Study