God's Timing and Purpose

I'm continuing my slow reading of Genesis.  When I started Genesis 17 today, I noticed that Abram was 99 years old when he encountered God (this time).  God reminded him of the covenant between them, and told him that he would make Abraham "exceedingly numerous."

Abraham laughed.

I turned back to Genesis 12, where Abram and God have their first recorded encounter.  God promised him land and descendants as part of their covenant.  In this chapter, Abram was 75 years old.

Twenty four years have passed between Genesis 12 and 17. 

I wonder what kind of faith will continue to believe God when he makes the same promise, 24 years later.  It is a lesson in accepting God's timing and in continuing to trust God when God's timing and our timing is not the same.

God does follow through with his promises, but he has waited 24 years.  At this point, when God does give Abraham and Sarah the gift of Issac, it is done at a time when there is no doubt that God is involved.  We know that this could not have been accomplished through human work alone.