The Epistle to Galatians is a book of the New Testament. It is a letter from Paul of Tarsus to a number of early Christian communities in the Roman province of Galatia in central Anatolia. It is principally concerned with the controversy surrounding Gentile Christians and the Mosaic Law within Early Christianity. Along with the Epistle to the Romans, it is the most theologically significant of the Pauline epistles, and has been particularly influential in Protestant thought.