Tertullian, Against Marcion 17

Consider the evidence and you see the whole order of God the Judge laid bare—or, to put it more precisely, the defender of that catholic and supreme goodness which the Marcionites refuse to acknowledge in the same God who sends rain on the good and the evil alike and makes his sun rise on the just and the unjust (Matt. 5:45), a generosity no other god even attempts. Marcion had the audacity to cut this very testimony of Christ about the Creator out of his gospel, but the world itself is written large and every conscience reads it. That same patience of the Creator will stand as evidence against Marcion on judgment day: the patience that waits for a sinner's repentance rather than his death, that prefers mercy to sacrifice. It turned aside the doom decreed for Nineveh, granted Hezekiah an extension on life in answer to his tears, and restored the Babylonian tyrant's kingdom after he repented. This is the mercy that spared Saul's son at the people's pleading, that pardoned David when he confessed his crime against Uriah's house, that restored Israel every time it judged her and recalled her every time it rebuked her. So do not merely stare at the Judge; turn and conform to his supreme example. Mark when he avenges, weigh when he spares; set his gentleness against his severity. When you have taken the measure of both in the Creator, you will find in him the very quality that drove you to invent a second god. Come now, finally, to a close inspection of his teachings, disciplines, precepts, and counsels. You may object that these are merely the stuff of human law codes. But Moses and God preceded every Lycurgus and Solon; no later generation fails to receive from the origins. Still, my Creator did not learn his legislation from your god: 'You shall not kill; you shall not commit adultery; you shall not steal; you shall not bear false witness; you shall not covet your neighbor's goods; honor your father and your mother; and love your neighbor as yourself' (Deut. 5:6–21). To these chief counsels of innocence and chastity, justice and piety, are added precepts of sheer humanity: every seventh year servitudes are dissolved into freedom; at that same time the field is left fallow to give the needy a place; even the ox treading the grain has its muzzle loosened so it may eat of the fruit of its present labor—so that humanity, rehearsed on beasts, might be more easily taught for the relief of human beings.