Development of the concept. The word in classical Greek means either simply to “stand apart”, to “depart”, or to “abandon an alliance”, to “revolt”. In the Jewish tradition it was then used to signify “abandonment of belief’, “infidelity to Yahweh”; so Jos 22:22; Jer 2:19; 2 Chr 29:19; see also Acts 21:21 and 2 Thess 2:3, where Paul is reproached with having rejected the Torah. It was then the obvious word to use to speak of abandonment of the Christian faith. Tertullian (De Pudicitia, 8: PL, II, 1047) calls the Jews “apostatae filii”; cf. “dabis apostatae veniam” (De Pudicitia, 6: PL, II, 104…