God comforts us in our afflictions, through fellow believers. I (Paul) boast in you, and hope you boast in us, even though I couldn't come to you. God has kept all His promises to us in Christ, and sealed them with His Spirit.
I didn't write before to hurt or offend you, but out of love. If the offender has repented, then forgive him, and I too forgive. Christ always goes before us, wherever we go.
The church of Corinth itself is our commendation of us. We need not write a letter. The ministry of the letter (the Old Testament) is surpassed in glory by that of the Spirit, anyway: more glory, more boldness even than Moses, more permanent than the first covenant. We are transformed from one glory to another.
We don't veil or spin the message, but preach Christ, who shines as a treasure within the clay jar of our selves. We are afflicted with suffering and death while we minister life to you. He will raise us to life again, while grace increases to you, bringing thanks and glory to God. The affliction is light and temporary compared to the eternal weight of glory coming.