The Epistle of Paul the Apostle to the Galatians, written in A.D. 57 or 58, probably from Antioch, is the cornerstone of Christian freedom. In Galatians Paul tells of his own conversion and of how he stood firm in his belief that Christ was the Savior of people everywhere, not just those who observed every detail of the Jewish law.

Galatians 4

4:28 Now we, brethren, as Isaac was, are the children of promise.