Several kinds are spoken of in the scriptures. (1) Epistles of commendation, which were letters by which travelers were commended by one branch of the Church to the members of another branch, as in Acts 18:27 and 2 Cor. 3:1. (2) A letter or decree such as that announcing the decision of the Jerusalem conference negating circumcision as a requirement for Gentiles to become members of the Church, as mentioned in Acts 15:23–29; 16:4; 21:25. (3) An epistle in its best sense is more than a letter; it is a formal teaching instrument. Twenty-one of the 27 books of the New Testament are epistles. See General Epistles; Pauline Epistles.