Is specifically related to Paul in this passage and goes along with Acts 9:16.
For I will show him how many things he must suffer for my name's sake."
The apostle Paul is describing his fight against the unbelievers and all the pain and suffering they have physically and mentally emotional pain they have brought upon him.
It was because
The god of this age has blinded the minds of unbelievers so they cannot see the light of the gospel of the glory of Christ,
The apostle Paul suffers more than any other man who has brought The glory of God that's displayed in Christ face.
For God, who said, “Let light shine out of darkness,” a made his light shine in our hearts to give us the light of the knowledge of God’s glory displayed in the face of Christ.
7But we have this treasure in jars of clay to show that this all-surpassing power is from God and not from us. 8We are hard pressed on every side, but not crushed; perplexed, but not in despair; 9persecuted, but not abandoned; struck down, but not destroyed. 10We always carry around in our body the death of Jesus, so that the life of Jesus may also be revealed in our body. 11For we who are alive are always being given over to death for Jesus’ sake, so that his life may also be revealed in our mortal body. 12So then, death is at work in us, but life is at work in you.
They carry in themselves Christ's death in the sense that they suffer as He did and for His sake, but they also carry Christ's life as evidence that His power is at work in them (2 Corinthians 4:7–12).
Romans 6 deals with every believers death to sin and the law by being baptized Christ Death and resurrection. Of course learning to walk by faith in that truly brings life and peace manifested. To apprehend those truths is certainly a fight that takes place mostly in our minds as they are being renewed.
Thanks for bringing attention to this question because it really made me more aware of how Christ's life was revealed in Paul and how he completed his sufferings in him for us!
There's just a couple other scriptures that go along with that.
To reveal His Son in me so that I might preach Him among the Gentiles,
Now I rejoice in my sufferings for your sake, and in my flesh I am filling up what is lacking in Christ’s afflictions for the sake of his body, that is, the church,
Grateful to God what he did through the apostle Paul for all of us who would come to believe in Christ because of his fighting the good fight fight of faith.