At the close of the letter, Paul summarizes his instructions to Timothy in this personal appeal (which begins, literally, "O Timothy"). The language Paul uses sheds some additional light on the nature of Timothy's mission and the gravity of the situation.
Paul has used special terminology to describe Timothy's task. First, what the NIV translates as guard what has been entrusted to your care is literally "guard the deposit." This phrase, which in the New Testament is limited to 1 and 2 Timothy, comes from a rather formal procedure (a "sacred trust") that was current in Greek, Roman and Jewish societies. One could securely pass some commodity to another party by entrusting it to an authorized agent. Some commentators interpret the "commodity" in this case to be Timothy's ministry as a whole. But as the contrast with the false teaching here and in 2 Timothy 1:13-14 suggests, it is more likely that Paul means "the faith" or "the gospel" that was under attack by false teachers.
Second, Paul's language emphasizes continuity. Timothy was to carry on with a mission given by Christ to the apostles much earlier (compare 1 Cor 15:1-3; 2 Tim 2:2). The gospel ministry is a single (though multifaceted) task with a single message, which is to be transmitted through the generations by servants whom God chooses (2 Tim 2:2).
Third, this task is a sacred one, as Paul's choice of "deposit" terminology confirms. God has planned that the evangelistic mission be executed by the proclamation of the gospel. The mission depends on the gospel message. Consequently, God's servants in each generation must guard it--that is, faithfully proclaim and protect it. The threat to the message and the church's mission posed by the false teachers in Ephesus was Paul's main reason for writing.
The closing description of the heresy also sheds some additional light. Because of the dangers involved in the heresy, aptly illustrated in the lives of some prominent Christians who destroyed their faith (1:20; 2 Tim 2:17), Timothy must avoid it. Turn away, however, does not mean refrain from confrontation. Rather, this action represents the conscious decision not to become involved in or even contemplate the false doctrine.
Paul denounces it as godless chatter. Not only does it have nothing to do with God or godliness, but it is also foolish nonsense (1:6; 4:7). It may have been systematic, but in comparison with the "standard" gospel, and given the results it brought--argument, speculation, inconsistent behavior and so on--it was no more than profane nonsense.
But Paul's description reveals another clue to its nature. Falsely called knowledge is a reference to one of the errorists' catchwords, gnosis. This was indeed a misnomer, for its message contradicted the gospel. One specific point of contradiction presents itself in their belief concerning the resurrection of believers (2 Tim 2:18). Their choice of the word knowledge to describe their doctrine is no sure connection to later Gnosticism. It does reveal, however, that what one "knew" rather than what one did determined one's spiritual status. From this came their negative view of the physical world (4:3) and other perversions of behavior. In correction Paul used another form of the word knowledge, epignosis, in reference to "the" knowledge of God that affects all dimensions of human life (2:4; 4:3; 2 Tim 2:25; 3:7; Tit 1:1).
Finally, the false doctrine was also destructive. Paul alludes to some (1:20; 5:15) in the community who professed the new teaching and wandered from the faith. Paul's concern was not only for the church's mission but also for the salvation of individuals. Cults have always had various ways to attract new members. Those cults that make any use of the Bible inevitably twist its message, and Christians who are not well grounded in the faith can be taken in by an atmosphere of camaraderie or promises to give meaning to life. Whatever the trap, the victim is set to wandering off course, farther and farther into uncharted waters. This is a warning to all of God's servants, and for Christian leaders it is a motivation to more urgent service.
In an abrupt closing, grace be with you [all], the apostle places Timothy and the entire community in God's loving care. As in the letter's opening greeting (1:2), grace signifies the whole of God's love and care for his people, coming to those who cannot earn it--an encouraging reminder that despite the awesome responsibility to pursue godliness in all parts of life, the Christian stands by grace alone. What Paul has said to Timothy and the Christian leaders he has said to all.