Tertullian (c. 160 – c. 225): In short, faith in one of two gods cannot possibly admit us to the dispensation of the other, so that it should impute righteousness to those who believe in him, and make the just live through him, and declare the Gentiles to be his children through faith. Such a dispensation as this belongs wholly to Him through whose appointment it was already made known by the call of this self-same Abraham, as is conclusively shown by the natural meaning. Tertullian, Against Marcion, Book 5, Chapter 3