- The Epistle to the Galatians is the ninth book of the New Testament of the Christian Bible and the fourth of the Pauline epistles in traditional arrangement. It is a letter from Paul the Apostle to a number of Early Christian communities in Galatia. Scholars have suggested that this is either the Roman province of Galatia in southern Anatolia, or a large region defined by Galatians, an ethnic group of Celtic people in central Anatolia. The letter was originally written in Koine Greek and later translated into other languages.