Verses one through three constitute a prologue in which Paul wishes divine favor to be showered on Timothy. He desires that his pupil receive grace, mercy, and peace from God. The phrase '...according to the promise of life in Christ Jesus...' may be indicative of the apostle knowing that he was soon to face martyrdom.
In verses four through seven, we read of Paul wanting to visit Timothy in order that he himself be filled with joy and to encourage his younger companion to remain strong in the face of intimidating circumstances. It is also worth noting that Timothy had a godly upbringing. He had exposure to the Old Testament Scriptures since childhood (2 Timothy 3:15).
Verse nine is theologically rich content. The Phillips New Testament in Modern English accurately captures the thrust of this passage: "Before time began he planned to give us in Christ the grace to achieve this purpose, but it is only since our saviour Jesus Christ has been revealed that the method has become apparent." God has made known to us the way to a holy life through Christ. That was His plan from eternity past. It is by the grace of God that we are able to bring glory to His name.
In verses twelve through fourteen, the Apostle Paul says that Christ appointed him to preach the gospel to a lost and dying world. He endures suffering for the cause of Christ, yet remains bold in doing this work. Paul urges Timothy to carry on the ministry that he handed on to him, to follow his life example. He expresses full confidence in the power of Christ.
In verses one and two, Paul tells Timothy to pass on what he had been taught to others who were faithful so that the work of ministry could make further progress. The latter was to labor in preaching the Word of God just as the former had done.
The apostle uses a soldier on active duty, athletic competitors, and a farmer as illustrations to make the point that our loyalty to God gets His approval. That is what truly matters. It is very much worth being persecuted in this life to be rewarded by Him in eternity. Being imprisoned as was the case with Paul cannot stop the seeds of the gospel from growing. We strive against sin in order that we bring glory to God.The New English Translation has this footnote: "sn If we are unfaithful…he cannot deny himself. This could be (1) a word of warning (The Lord will exact punishment; he cannot deny his holiness) or (2) a word of hope (Because of who he is, he remains faithful to us despite our lapses). The latter is more likely, since Paul consistently cites God’s faithfulness as a reassurance, not as a warning (cf. especially Rom 3:3; also 1 Cor 1:9; 10:13; 2 Cor 1:18; 1 Thess 5:24; 2 Thess 3:3)."
Paul calls on Timothy to be a man of integrity (2 Timothy 2:15). He must be a man of virtue. He must avoid profane arguments that distract from godly living (2 Timothy 2:16). Verse 17 tells us that this corrupt form of conversation spreads "like gangrene" (New American Standard Bible and most other translations follow this rendering) or "like cancer" (New King James Version and few others take this rendering). The idea to be gathered from this is that such arguments are spiritually deadly and contaminating.
Timothy must pursue purity of heart. He must flee from fleshly lusts (2 Timothy 2:22). He must pursue '...whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy..." (Philippians 4:8). Timothy had to put whatever he heard from the Apostle Paul into practice. We must be holy if we desire to be a vessel of honor for God (2 Timothy 2:21).
Verses one through five offer a general description of fallen humanity in terms which are self-explanatory: "...lovers of self, lovers of money, boastful, arrogant, slanderers, disobedient to parents, ungrateful, unholy, unloving, irreconcilable, malicious gossips, without self-control, brutal, haters of good, treacherous, reckless, conceited, lovers of pleasure rather than lovers of God..." That is the spirit of the age which we ought to steer clear from.
Verse thirteen describes the judicial hardening of the heart that God pronounces on those who are impenitent. These are people who continually blaspheme God. They reject His offer of grace and so they 'wax themselves worse' over time. These godless people deceive themselves and others around them. Compare with Romans 1:24-26.Is all Scripture a better reading of 2 Timothy 3:16 than is every Scripture? Henry Clarence Thiessen writes, "...The translation, "Every scripture inspired of God is also profitable," etc., is open to several criticisms: its rendering of pasa graphe and of kai, and its disposition of the verbal adjective theopneustos. Robertson says, with abstract substantives, proper names, and single objects pasa is tantamount to "all"; and "since graphe is sometimes regarded as definite pasa graphe (2 Tim. 3:16) can be "all Scripture" or "every Scripture'." Lock so translates it. Other considerations make this the preferable reading. There is no copula in the Greek text, but we have to insert one in the translation. The rendering we are criticizing treats theopneustos as an attributive and so inserts the copula after "God." This requires that the particle kai be rendered as "also," an adjunctive participle. Now "also" implies that we are adding one co-ordinate idea to another; but the words "is also profitable" are not an addition to anything that goes before, It is better, therefore, to treat theopneustos as a predicate and to insert the copula after "Scripture." The statement will then read as it is in the Authorized Version: "All Scripture is inspired of God and is profitable," etc. In other words, the correct rendering of this verse makes Paul teach the full inspiration of the entire Old Testament." (Introduction to the New Testament, p. 87-88)
What exactly is the nature of heavenly rewards? C.S. Lewis, in Mere Christianity, book 3, chapter 10 (on “Hope”), says, "There is no need to be worried by facetious people who try to make the Christian hope of “Heaven” ridiculous by saying they do not want “to spend eternity playing harps.” The answer to such people is that if they cannot understand books written for grown-ups, they should not talk about them. All the scriptural imagery (harps, crowns, gold, etc.) is, of course, a merely symbolical attempt to express the inexpressible. Musical instruments are mentioned because for many people (not all) music is the thing known in the present life which most strongly suggests ecstasy and infinity. Crowns are mentioned to suggest the fact that those who are united with God in eternity share His splendour and power and joy. Gold is mentioned to suggest the timelessness of Heaven (gold does not rust) and the preciousness of it. People who take the symbols literally might as well think that when Christ told us to be like doves, He meant that we were to lay eggs."