God will provide.

7    Isaac spoke to Abraham his father and said, "My father!" And he said, "Here I am, my son." And he said, "Behold, the fire and the wood, but where is the lamb for the burnt offering?"
8    Abraham said, "God will provide for Himself the lamb for the burnt offering, my son." So the two of them walked on together.

Genesis 22:7-8

This first recorded conversation between Abraham and his son Isaac is poignant and a testament to faith. God had instructed Abraham to offer his only son of the promise as a burnt offering. And Abraham believed that obeying God in this was what he should do. When Isaac asks this question, Abraham is not lying. I believe Abraham saw this for what it was: as test of faith.

In the New Testament, the book of Hebrews comments on this episode and offers insight into Abraham’s faith: he believed God would raise Isaac back. After all, God had already promised that Isaac was the son of the promise. So if God took him in sacrifice, God would have to raise him up because God does not lie. And so an old man and his young son walk on up the mountain to build an altar.

And God did put Abraham’s resolve to the test. Dramatic tension increases as Isaac helps prepare the altar and the wood, and then the old man binds his son and lays him on the altar, ready with knife to kill him like a lamb and burn him in sacrifice. It is then that God stops the action, pronounces satisfaction on the ancient faith of Abraham, and does exactly what Abraham prophesied: a ram is caught in a thicket to be sacrificed in Isaac’s stead.

Of course this is not a passage to be literally applied. The resulting trauma to any child (outside of the call of God) would be abusive. But I can see times in which God has called me to obey, to wait through the seemingly unthinkable until He has provided. And it is always worth the wait because God will provide.