I will therefore not speak of gods at all, nor of lords, but I shall follow the apostle; so that if the Father and the Son, are alike to be invoked, I shall call the Father "God," and invoke Jesus Christ as "Lord." But when Christ alone (is mentioned), I shall be able to call Him "God," as the same apostle says: "Of whom is Christ, who is over all, God blessed for ever."
Source: Against Praxeas