They had to remember and recognize his apostolic credentials. By the will of God strengthens the point. Paul was not an apostle by the decision or desire of any man, including himself. Paul was an apostle by the will of God.
Context and Background of 2 Corinthians
Who wrote the book?
These are all of the chapters of the book of 2 Corinthians. Clicking on a chapter will show you the text of that chapter of 2 Corinthians in the Bible New International Version. External and internal evidence confirms that this letter was written by the Apostle Paul to the church at Corinth. This authorship has never seriously been in question, as it is quoted by early church fathers Polycarp, Irenaeus, Clement of Alexandria, and Tertullian. Second Corinthians is a personal, emotional, and at times painful letter was written by Paul to the church at Corinth. As we read this letter, it is clear that some in Corinth rejected what Paul wrote to them in 1 Corinthians, to their own detriment.
The epistle is attributed to Paul the Apostle and a co-author named Timothy , and is addressed to the church in Corinth and Christians in the surrounding province of Achaea , in modern-day Greece. While there is little doubt among scholars that Paul is the author, there is discussion over whether the Epistle was originally one letter or composed from two or more of Paul's letters. Although the New Testament contains only two letters to the Corinthian church, the evidence from the letters themselves is that he wrote at least four and the church replied at least once:. The abrupt change of tone from being previously harmonious to bitterly reproachful in 2 Corinthians 10—13 has led many to speculate that chapters 10—13 form part of the "letter of tears" which were in some way tagged on to Paul's main letter. The seemingly sudden change of subject from chapter 7 to chapters 8—9 leads some scholars to conclude that chapters 8—9 were originally a separate letter, and some even consider the two chapters to have originally been distinct themselves. Other scholars dispute this claim, however.