The epistles of the New Testament are Christian writings of Apostles to churches in particular parts of the world. The most prolific apostle to write was Paul.
There are epistles that are written to particular areas, and general epistles that are written to groups. Paul wrote more epistles to particular churches of a geographical area, as well as personal letters to Timothy and Titus. Peter, John, James, Jude, and the writer of Hebrews wrote general letters to the church in general. Sometimes these epistles are divided into subgroups. For instance, the "prison epistles" are the ones written by Paul while he was in prison, while the "pastoral epistles" are the letters to Timothy and Titus, since they contain advice about providing pastoral care to their churches.
These are letters written by some very early Christian leaders, in the first or second century, which are not part of the New Testament. They are generally considered to form part of the basis of Christian tradition. The word epistle is used partly because these were all written in Greek, in a time period close to when the epistles of the New Testament were written.
New Testament Epistles
Epistles of certain apostolic fathers