By faith, with Sarah's involvement, he received power of procreation, even though he was too old, because he considered him faithful who had promised. Therefore, from one person, and this one as good as dead, descendants were born, "as many as the stars of heaven and as the innumerable grains of sand by the seashore" (Hebrews 11:11-12).
The Heidelberg Catechism defines true faith as "not only a knowledge and conviction that everything God reveals in his Word is true; it is also a deep-rooted assurance, created in me by the Holy Spirit through the gospel, that, out of sheer grace earned for us by Christ, not only others, but I too, have had my sins forgiven, have been made forever right with God, and have been granted salvation" (A 21).
The author of Hebrews would probably not disagree with this definition. However, I suggest, recognizing that I am skating on thin ice, that according to Hebrews 11, more should be added to this confessional definition.
Hebrews 11 faith often involves a physical response to God. It involves action taken in response to the unseen God and his promises. Faith is not merely static belief or cognitive assent. It spurs us to act in accordance with God's truth. There is a boldness to faith that caused Noah to build an Ark, Abraham to leave home and Moses' parents to hide their son. This courage is rooted in the faith that, in the end, God will come through; he will keep his promises.
The folks mentioned here stepped forward with eyebrow-raising tenacity and confidence. There was no perceptible reason for doing so, except that God had spoken. God revealed himself, and that was reason enough to act. Their faith caused them to behave in certain ways, in ways expectant of promises fulfilled.
Along with the promise of a new homeland, God promised Abraham children. Well, there was only one thing to do with that promise. But this promise tested Abraham's faith severally. He got very old, and so did Sarah; well beyond childbearing age. God continued to promise, and Abraham kept working on his faith. Finally, he was enabled to become a father because he believed God.
Abraham, an old man, and Sarah, his wife, as good as dead, became parents, trusting in the faithfulness of God. We are challenged to take our eyes off the obvious—in this case the inability of old people to become pregnant—and to focus on the faithful God who keeps his promises.
There is more hidden in this promise. The number of Abraham and Sarah's descendants would continue to expand until their children included not just those of their blood line, but all those with their kind of faith. Paul said it best, "Understand, then, that those who have faith are children of Abraham" (Galatians 3:7).
As the Catechism put it, true faith "is also a deep-rooted assurance, created in me by the Holy Spirit through the gospel, that, out of sheer grace earned for us by Christ, not only others, but I too, have had my sins forgiven, have been made forever right with God, and have been granted salvation." All those with this faith are children of Abraham and recipients of the promises God made to him.
The question remains, how will that faith effect the way that we live?
As you journey on, go with the blessing of God:
May the peace of the Lord Christ go with you: wherever he may send you. May he guide you through the wilderness: protect you through the storm. May he bring you home rejoicing; at the wonders he has shown you. May he bring you home rejoicing once again into our doors.