After telling Timothy to endure hardness as a good soldier of Christ (2:3), Paul knew that Timothy might be thinking that soldiers often die in the line of duty. So he reminds him that if that happened to him, God would raise him from the dead by reminding Him of the resurrection of Christ (2:8). He calls Him “the seed of David” to remind Timothy that God swore to David that He’d raise up David’s seed (Acts 2:29,30). God sometimes says things and repents, but not when He swears, so Paul called the Lord’s resurrection “the sure mercies of David” (Acts 13:33,34). And now that Timothy was in Christ, those sure mercies applied to him too—and to us! (cf. Ps.56:4).
Christ was raised according to Paul’s gospel (2:8), that is, He was raised “for our justification” (Rom.4:25). But your justification only becomes effectual if you believe He died for you and rose again (Rom.10:9). But this begs a question. How could Christ have been raised according to Paul’s gospel if He rose before Paul had a gospel?
This is God’s way of telling us that He knew Paul’s gospel in advance, and raised Christ according to the blueprint of his gospel that He drew up in Heaven in eternity past. This explains how God can someday judge the sins of even Old Testament men by his gospel (Rom. 2:16). But just as you don’t have to know antivenom saves you from snake bite, so the Old Testament believers didn’t have to know how obeying the gospel that God gave them saved them, and they’ll be judged according to the fact that provision was made for their salvation which they failed to access by faith.
Remembering Christ’s resurrection according to Paul’s gospel (that He was raised for our justification) is the only way we should remember it in the dispensation of grace. Peter told the Jews to remember that He was raised to sit on David’s throne (Acts 2:29,30). He was born to sit on David’s throne (Lu.1:32), but when the Jews killed Him that prophecy was in jeopardy until God raised Him to sit on David’s throne. But that’s not how we should remember Him. When we observe the Lord’s Supper, Paul says we should remember His death and resurrection (ICor. 11:24-26), but the Lord told the 12 to remember His death and resurrection in connection with the kingdom (Mt.24:28,29), something Paul doesn’t mention.
Paul suffered trouble preaching his gospel (2:8,9) because Satan doesn’t want men to know He was raised for our justification. As far as we know none of the 12 were in bonds at that time, for after God shifted His focused from them to Paul, Satan did too!
Paul didn’t mind though, for his bonds fell out to the furtherance of the gospel (Phil.1:12,13). He was imprisoned in Caesar’s palace and led some of the royals to the Lord (Phil.4:22). Since men had the right to appeal to Caesar (Acts 25:11), men from all over the empire were coming to Rome, hearing the gospel, and taking it home! This carried the gospel “further” than if Paul hadn’t been in jail.
The gospel was also furthered by Paul’s bonds through the brethren (Phil.1:14). Persecution doesn’t extinguish Christ-ianity, it fans the flames! That’s an example of Romans 8:28. God’s “purpose” is that the gospel be furthered, and all things work together for that good.
This is how Paul could be “content” in jail (Phil.4:11). Once you tie your contentment to the furtherance of the gospel, you too will be content, for God can further the gospel in whatever happens to you personally. It is actually the only way to be content. You’d think Haman would have been content when everyone worshipped him, but instead he was miserable because one man didn’t (Esther 3:1-6). This shows that no matter how perfect your life is, you won’t be content either. It is human nature. You must find your contentment in the furtherance of the gospel.
If you haven’t yet attained that level of spirituality, remember Paul too had to “learn” it (Phil.4:11). We know he wasn’t content when he went to jail, for he thought he had to be free for the word to have free course (IIThes.3:1,2). Once he learned otherwise, he was content.