Ep. 11. Genesis 21 | Child of Promise

EPISODE 11

CHILD OF PROMISE: GENESIS 21

We have already talked about the son of flesh (Ishmael), but in this chapter we are finally introduced to the son of promise (Isaac). Remember, these two sons depict two people groups and two covenants. Ishmael represents those who seek righteousness through their own efforts and those who will not believe in Jesus. Isaac represents those who pursue righteousness through the promise of God and the means of faith and grace, those who gladly put their faith in Jesus. Paul brings this truth to greater focus in Galatians 4 when he says of Hagar and Sarah (the mothers of the two boys in question), "The women represent two covenants. One covenant is from Mount Sinai (where the Law of Moses was given) and bears children who are to be slaves: This is Hagar." And "The Jerusalem that is above (the kingdom of heaven) is free, and she is our mother." In Romans, Paul states, "It is not the children by physical descent who are God's children, but it is the children of promise who are regarded as Abraham's offspring." It would greatly benefit us if we could understand the relationship between these two sons of Abraham and how they bear on our understanding of things related to faith and salvation.

You will doubtless note in Genesis 21:9 that Ishmael (the son of flesh and of slavery) mocked Isaac (the son of promise and faith). So, it stands true today that the people who put faith in Jesus as the means of salvation are mocked by those seeking to utilize their own efforts for righteousness. As a result of this mockery, Sarah is inclined to remove Hagar and Ishmael from the household, saying, "Cast out this slave woman with her son, for the son of this slave woman shall not be heir with my son Isaac." This was a pleasing decision in God's sight as he confirmed to Abraham, "Whatever Sarah says to you, do as she tells you, for through Isaac shall your offspring be named." When we look beyond the narrative of this story and plant ourselves in the spiritual depth of this statement, we find we have the answer to the question, "Who will be saved?" Only those like Isaac will be saved: people who believe in the promise of God and have put faith in God as the provider of salvation. For, "if you are Christ's, then you are Abraham's offspring, heirs according to the promise."

Returning to John 8, we see that Jesus said to the Pharisees, "The slave does not remain in the house forever, but the son remains." He says this to show these "sons of the Devil" that they were in slavery since they depended upon works of the Law for righteousness rather than the promise of God for salvation through Christ. We know that those who seek righteousness through works of the Law will not inherit what those who come to God by grace and faith have and will inherit. Again, we read, "At that time, the son born according to the flesh persecuted the son born by the power of the Spirit. It is the same now. But what does the Scripture say? 'Get rid of the slave woman and her son, for the slave woman's son will never share in the inheritance with the free woman's son.'"

So if we find ourselves tempted to rest on our own merits and good deeds as the means for salvation, we need only look to the narrative about Ishmael and Isaac to see there is no room for such a belief in our theology.

ADDITIONAL READING: Genesis 18:10-14; Galatians 3:31; Galatians 4: 21-31; Romans 9:1-9; Hebrews 12:18-24