In verse 4 Paul criticizes the errorists' myths and endless genealogies. As the term is used in the New Testament (always in the plural—1 Tim 4:7; 2 Tim 4:4; Tit 1:14; 2 Pet 1:16), myths is consistently a pejorative and polemical classification. It classifies material not simply as untrue or legendary but as pernicious in its (or its author's) purpose to justify immoral or improper behavior on the basis of a divine or traditional pattern. Thus grounds for certain immoral practices could be found in the behavior attributed to the gods. Paul uses the term similarly in the Pastorals to categorize the false teaching in Ephesus as dangerous and immoral. But the actual content of this false teaching is more clearly in view in the term that follows. Genealogies, as a description of a literary type, is broader in meaning than lists of families and descendants (such as 1 Chron 1—9; Mt 1:1-17; Lk 3:23-38); it referred to the part of history concerned with persons and so meant "personal histories or biographies" (so Quinn 1990:245). The false teachers probably used such stories to support their doctrine (see comment on 2:11-15), and their "knowledge" and its ethical demands were somehow linked to this source. The rabbis were well known for intricate and fanciful interpretations of such Old Testament texts. Several decades later an interest in the Old Testament "genealogies" is evident among a Gnostic sect called the Ophites.
While Paul does not elaborate, his reason for rejecting the false teachers' system is clear: instead of serving God's salvation plan, as proper interpretation of Scripture should, their esoteric approach causes only "controversy" (compare 6:4). Evidently their conclusions were not all readily accepted, and the debates and arguments that followed did more to divide than to edify the congregation. In fact, Paul goes on to say that God's "plan" of redemption (NIV has work; see Eph 3:9) is apprehended by faith, that of genuine believers, not by novel schemes of interpretation. And with this word (and what follows) Paul sets the beliefs and activities of the false teachers totally outside the bounds of true faith in Christ and service to God. For this reason Timothy must oppose the new interpretation.