In 2 Tim 1 Paul has told Timothy to model his life and ministry after Paul, recalling the examples of both his family (Lois and Eunice) and Paul’s co-worker Onesiphorus. He ought to avoid the example of the false teachers in Ephesus, namely Phygelus and Hermogenes (1:15) and Hymenaeus and Philetus (2:17).
In order to avoid these faithless men, Timothy is to train the elders to be “approved workmen” (2:14-19). In fact, Timothy is to be an approved workman before he trains others. Like Paul’s warning to Titus, Paul warns Timothy to avoid quarreling about words or other theological babble. On the one hand, this is a difficult command since one has to have defined the “core” of the Christian faith very well in order to decide what qualifies as “babble.”
On the other hand, sometimes the theological “babble” seems fairly obvious, mostly since it is the sort of thing people are passionate about! (Like the famous definition of pornography, I may not be able to define it, but I know it when I see it!)
“Do your best” (ESV) in v. 15 has the sense of being diligent in fulfilling an obligation (σπουδάζω), “make every effort” (BDAG). The KJV translated this word “study,” a word which has shifted considerably in modern English. The verb is used in Gal 2:10, for example, for the reminder to care for the poor. In Eph 4:3 Paul says that the believer ought to “be eager” to maintain the bond of unity. It is used twice in 2 Peter with the sense of diligence in spiritual development (1:10, 3:14). This word stands in contrast to being “diligent” in senseless theological babble. While the opponent in Ephesus is busy with their “endless myths,” Timothy is to be busy presenting himself as God’s approved workmen.
Timothy is to be an approved workmen, properly handling the word of God. 2 Tim 2:15 is classic verse for modern “noble Bereans” since it implies that the maturing person of God will become increasingly able to read the scriptures with intelligence and confidence. We sometimes talk about “learning a trade.” The more sone works and being a carpenter, for example, the better one gets.
The analogy is excellent since studying the Bible is a skill and an art. There are technical elements which can be taught and learned (parsing Greek verbs, reading background studies, finding parallel texts, etc.), but there is an art to knowing what to do with that information! An unskilled carpenter can build a bookshelf with boards and a few nails, but a master carpenter builds an excellent piece of furniture that is of great value.
The modern church has created a class of professional Bible interpreters. This gives the impression that the Bible is too difficult to fully understand without professional training. People in churches want to leave Bible reading to the professionals, the approved workmen. But this is not at all Paul’s point here. Timothy (and by analogy all believers) ought to be busy training themselves as best they can to handle the Bible correctly so that they will avoid the errors that are plaguing the churches in Ephesus.
That is the point of the phrase “rightly dividing” in the KJV. That translation is also not helpful, since the word refers to guiding the word of truth along a straight path (BDAG). Perhaps Pual has in mind a Roman Road that moves from one point to its goal, without any unnecessary deviation. So too the believer ought to read and study the Bible without being turned aside by wordy debates or impious talk.”
Paul’s point is that we ought to use the Scripture in a way that it was intended: do not twist scripture to make it say what you want it to say, or would prefer it to say.