Paul wrote about things that make a person unclean in body and spirit. Scholars think Paul was writing about any sin. Every sin makes a person unclean in body and spirit. That is, it makes them completely unclean.
When someone took advantage of another person, they cheated this person in some way. Often, they took money from someone (see: 2 Corinthians 12:17-18).
Paul said, “our bodies had no rest.” Some scholars think Paul was speaking about their whole person, that is, body, soul, and spirit, when he said “our bodies had no rest.” When he spoke about rest, he was speaking about people being free from troubles and conflicts.
There were two kinds of sorrow. “Godly” sorrow meant that people felt badly about their sins and later repented before God. “Worldly” sorry meant that people tried to hide their sins by blaming others or making excuses. They did not truly repent.
Paul wrote about salvation with regret. “Without regret”(ἀμεταμέλητος/g0278) meant that once the Corinthians repented of their sin and were at peace with God, they could be at peace. That is, it was a salvation that freed them from the judgment of God.
Paul wrote that the Corinthians were innocent. Scholars think that though the Corinthians did not immediately to correct someone who sinned. However, they did not sin in this way. Therefore, they were innocent of sinning in this way.
Titus went to Corinth in order to tell them to change their ways. The repentance of the Christians encouraged Titus. In this way Titus’ spirit was “refreshed”(ἀναπαύω/g0373).
Paul wrote about “fear and trembling.” He wanted people to honor, respect, and submit to Titus. Scholars think Paul was speaking about how the Christians in Corinth welcomed Titus with much honor and respect. That is, they knew Paul sent Titus to them. Because of this, God gave permission to Titus lead the Corinthians.
See: Mark 5:24-34; 1 Corinthians 2:2-5; Philippians 2:12