In Genesis 21:6, we are told that Sarah laughed for joy at the birth of her son Isaac. The grace and gifts of God bring joy and laughter to the grateful hearts of those who believe God and gladly receive what He has given them. But in verse 9, we see a different kind of laughter. This laughter is the laughter of mockery; it is the laughter of disdain for what God has done in the lives of those who believe Him coming from the mouths of those who do not. It is the ridicule that comes from the heart which has only known the fruits of its own efforts and never the gracious fruits that come from God alone. This is the contempt which the man who lives in the flesh holds for the man who walks after the Spirit of God.
Before this particular incident, we have not been told very much about the nature and character of the young man Ishmael, whom Abraham became the father of by Hagar the servant woman. But this solitary verse truly speaks volumes. He complied with his father’s wishes and became circumcised a few years before this (Genesis 17:26) in accordance with the command of God. He went through the motions of religious observance, paying lip-service to the commandments of God, yet we see now that his heart was far from Him. The unrepentant, unregenerate man will very often perform the ceremonies and rituals which he feels make him appear to be religious; yet when he is confronted with the genuineness of God’s unmerited grace, he scoffs at it and mocks the one who receives it.
The man of the flesh seeks to come to God through his own efforts. He has no realization, no concept of the unearned grace which alone can serve as the force which makes a person acceptable to God. Ishmael looked upon the birth of Isaac as something foolish and disdainful much as those who reject Christ see the Cross as something foolish and meaningless (1 Corinthians 1:18). Both will revere and regard their own efforts and their own self-perceived merits as something of great importance, all the while mocking and ridiculing the grace of God which alone has the power to save.
Upon witnessing the spectacle that Ishmael is putting on during what should be a very joyous occasion, Sarah demands that Abraham send away the young man and his mother. This slave woman’s son shall not be heir with my son!, she proclaims. So the enmity between Ishmael and Isaac, between Sarah and Hagar, precludes any accommodation between the two families. They simply cannot peacefully co-exist. The Apostle Paul will use this whole incident as an illustration of the incompatibility between living under Law and living under Grace (Galatians 4:21-31). These two are wholly irreconcilable, as well. One must choose whether they will live under Law or live under Grace.
“Nevertheless what saith the scripture? Cast out the bondwoman and her son: for the son of the bondwoman shall not be heir with the son of the freewoman.” (Galatians 4:30)
In light of this clear imperative, it is puzzling that there are those who name the name of Christ who claim to live under Grace yet still attempt to fulfill the works of Law. Often, such claim that God provides Grace but still expects us to live under Law. Whether it be some observance of Old Testament dietary regulations or the keeping of Sabbath days, they claim that the Christian is in essence under a mixture of Law and Grace. But we see that Ishmael was cast out completely; he did not remain close by, he did not pay occasional visits to the family. Ishmael, representing the Law, was entirely put away once the son of Grace, the heir of promise came. There was not room for both within the household of Abraham, neither is there room for both in the household of God. The Law has served its purpose in the plans of God (Galatians 3:24-25), it holds no place anymore for those who have received the Son of Promise, Jesus Christ. The self-effort of ritual, religious motion, and attempted observance of Law will never make anyone acceptable to God, nor can it ever bring Salvation. Let us cast out the son of the bondwoman and place our faith firmly in God’s Grace, lest we, too, be found mocking.