Remember Jesus Christ, risen from the dead, the offspring of David, as preached in my gospel, for which I am suffering, bound with chains as a criminal. But the word of God is not bound! Therefore I endure everything for the sake of the elect, that they also may obtain the salvation that is in Christ Jesus with eternal glory. The saying is trustworthy, for:
If we have died with him, we will also live with him;
if we endure, we will also reign with him;
if we deny him, he also will deny us;
if we are faithless, he remains faithful—
for he cannot deny himself.2 Timothy 2:8-13
What does Paul say next? "Remember Jesus Christ". What is it to be remembered about Jesus Christ? First, he was "risen from the dead". Second, he's "the offspring of David". So he defeated death and rose as he said he would. Also, he is the offspring of David which is a fulfillment of scripture. This Jesus is the one Paul preached.
It is for what he is preaching that he is suffering. Specifically, he is currently in chains because of what he is preaching. However, Paul makes an interesting statement "But the word of God is not Bound!". Paul may be bound in chains, but unlike Paul, God's word is not bound. There is hope in God's word even if he is in chains and so Paul endures. He endures for the sake of the elect. Those whom God chose in ages past that he would graciously save. Paul endures for their sake that they might be saved. That actually sounds a bit odd. If they were chosen in eternity past, why would Paul need to endure for their sake what has already been set? Well, they still need to hear the gospel and God is using Paul as his instrument to save. Also, Paul doesn't know who the elect are and he needs to simply preach for the sake of souls he doesn't know whether or not they will be granted repentance leading to a knowledge of the truth.
Paul presents a saying that I guess is relating to what he has said.
The saying is trustworthy, for:
If we have died with him, we will also live with him;
if we endure, we will also reign with him;
if we deny him, he also will deny us;
if we are faithless, he remains faithful—
for he cannot deny himself.2 Timothy 2:11-13
Dying with Christ leads to living with him. Paul just mentioned Jesus raised from the dead. This also reminds me of Romans 6, talking about not continuing in sin. Why not? We have died to sin and were baptized into his death. This leads to be raised with him.
Enduring leads to reigning with him. Paul also just mentioned about enduring everything for the sake of the elect. He endures hardship and enduring leads to reigning with Jesus. It's not how you start but how you finish that counts and endurance is how you finish well.
Unfortunately, denying him leads to him denying us. Fortunately, if we lack faith, he is still faithful. Why is that? He cannot deny himself. We may fail but there is still hope because Jesus is faithful. He is who he says he is and does what he says he'll do.