In Paul's Isaac and Ishmael analogy, how is Ishmael different from Isaac?
Ishmael represents the flesh, the earthly, and the bondwoman Hagar, standing for law and legalism. Isaac represents the spiritual seed, the promises, grace, and freedom. Scripture says the son of the bondwoman cannot be heir with the son of the free woman; the two cannot share an inheritance.
Les explains that in Galatians chapter 4 Paul uses the analogy of Isaac and Ishmael. Ishmael was of the flesh, he was earthly, not of the spiritual seed, and not of the promises as Isaac was. Hagar and Ishmael stood for the law, they stood for that which is of the flesh. Paul quotes Scripture: cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the free woman. Ishmael and Isaac could have no consort or interrelationship, because Ishmael stood for the law and legalism, while Isaac stood for grace and freedom.