2 Corinthians 1 to 7
Second Corinthians is a very personal epistle, as Paul responds to those who attacked him. It also teaches doctrines such as mercy and forgiveness, suffering for Jesus’ sake, and Christian attributes.
“What does the expression “to walk by faith, not by sight” mean? (2 Corinthians 5:7),” by Richard D. Draper, at BYU New Testament Commentary
Paul’s point is that worldly appearance is not what defines the path the Christian should walk. Certainly, for him, it is not appearance that counts but serving the Lord no matter how such service might appear to the world.”
“Paul’s Use of Old Testament Scripture,” Jared L. Ludlow, in How the New Testament Came to Be
Paul used Psalm 116 in 2 Corinthians 4:13 to present the motivation for preaching: having believed, they must now speak. He evoked Deuteronomy, Leviticus, Isaiah, and 2 Samuel in his teaching that we are temples and children of God in 2 Corinthians 6:16-17.
Paul used Deuteronomy 19 in 2 Corinthians 13:1 as a proof of his calling. He used Jeremiah 9 in 2 Corinthians 10:17 to show that the teacher should not boast. He used Exodus 16 to teach equality (2 cor. 8:15), and Psalm 112 to teach that God will provide for all (2 Cor. 9:9).
"Suffering for the Savior's Sake," Aaron Snyder, Religious Educator 2010
Paul refers to his own conversion in 2 Corinthians 4:1-2, 5-6. He became an ambassador for Christ, as he says in 2 Corinthians 5:20. Paul sees suffering as a way to strengthen a testimony (2 Cor. 4:11; 12:7).