<p>12:16 <em>Ensure that no one is an immoral or Godless person like Esau, who for one meal sold his own birthright</em>- The false teachers of :15 are associated with immorality; and this connection is seen throughout the New Testament warnings against false teachers. They were not simply intellectually mistaken. There was a moral issue too; Judaism was attractive even to Gentile converts in places like Corinth and Ephesus because the idea of justification through a few rituals opened up the way to behave immorally in other areas of life which were outside the circumference of the rituals. The Hebrew Christians had identified with Isaac, the true seed; and thereby with Jacob too. It was Judaism which was the illegitimate seed of Abraham, associated with Hagar (Gal. 4), the illegitimate children of :8. By returning to Judaism they were selling their birthright for temporal benefit of the moment- the apparent safety from Roman and Jewish persecution. Judaism is here called &quot;Godless&quot;, just like Esau, despite his public attempts to be pleasing to his father Isaac by choosing wives he thought might please them. Esau was the firstborn, but he threw this away. The Lord Jesus is the &quot;firstborn&quot; of all creation, a form of the same Greek word used for &quot;birthright&quot;. The believers are counted as the firstborn who were saved by the Passover lamb (11:28), and thus are &quot;the church of the firstborn&quot; (:23). But they were giving away that birthright for temporal benefit, just as many do today in different contexts.</p>