“The letters” in the New Testament refer to a collection of 21 letters (or epistles) written by various authors to different individuals or Christian communities in the first century AD. These letters make up a significant portion of the New Testament, and they were written in the Greek language.

The letters in the New Testament can be divided into two groups: Pauline and non-Pauline. The Pauline letters are those that are attributed to the Apostle Paul, who was one of the most influential figures in the early Christian church. There are 13 letters that are considered to be Pauline, and they include Romans, Corinthians (1 and 2), Galatians, Ephesians, Philippians, Colossians, Thessalonians (1 and 2), Timothy (1 and 2), Titus, and Philemon.

The non-Pauline letters were written by other authors, including Peter, James, John, and Jude. These letters include 1 Peter, 2 Peter, 1 John, 2 John, 3 John, James, and Jude.

The letters in the New Testament were written to address various issues and concerns that arose in the early Christian communities, such as questions of doctrine, ethical behavior, and the role of leadership within the church. They are considered to be important sources of information about the beliefs and practices of the early Christian church, and they continue to be studied and interpreted by scholars and believers today.