We find a conversation between Abram, who now becomes Abraham and God. In this conversation we find God once again promising a covenant between he and Abraham. But this time it is a conditional covenant where God promises a progeny that will include kings and would be so numerous that they will not be able to be counted. God demands circumcision as a sign of faithfulness of the people to God. In the midst of this conversation and promise Abraham and Sarah have their names changed. That is a big deal. We find God changing names throughout Scripture and it always means that God has made an impact upon that person and their future. This is the beginning of that whole name change thing.
Notice how Abraham takes the news of the covenant and the promise from God in vs. 17. “Then Abraham fell on his face and laughed.” Not really the approach that I would encourage when God gives us a promise that we absolutely know that he will keep. We really should not laugh at or mock God. I’m just saying. Abraham found humor in that he, at 99 and Sarah at a similar age would have children. But God, just use Ishmael. God says, I will, don’t worry, he will be blessed, but it will be through a son that you are to call Isaac that I will bless you and establish the covenant. The promise is made, the stage is set for Abraham to take his child Ishmael, and all of his servants and slaves, those born in his house and those bought from foreigners, to be circumcised. Ishmael was thirteen when this took place. We find ourselves set up for Ishmael to get kicked out of the camp and to establish himself and to be blessed by God.
So, it is interesting how the great monotheistic religions: Judaism, Christianity, and Islam all point to these beginning chapters of Genesis as the beginning of their road as people chosen by God. The Israelites look at Father Abraham as the patriarch. The Christians look to Abraham and his son Isaac specifically as the route through which Jesus took to be the Savior of the earth. The Muslims see Abraham and Ishmael as the route that was taken to make them the people of God.
We will look at circumcision again in the future, although this is the origin of it. Well, let’s just handle it now. It is used to mark and seal the men of God as the people of God. As Christians we see baptism as serving the same purpose, except its scope goes well beyond the gender lines established in circumcision. This is why within our Reformed church we understand child baptism as important because it does take the place of the circumcision in that it distinguishes each child, male or female, as being a child of God. This sacrament for us is crucial to understanding how we are involved in a process that has seen its origin in Abraham and so we are included as children of God. Baptism is the Christian step to the sign and seal of God’s grace as circumcision was the step taken by those of Israel to serve as a sign and seal of God’s grace in the covenant. The message is the same for both circumcision and baptism, although baptism is much more inclusive.