What are you willing to sacrifice?

"Go to the mountain and sacrifice your one and only son."

These were essentially the same words Abraham heard from the Lord.  As you know Isaac was Abraham's one and only son, a son born when Sarah and he thought they were beyond the age to be bearing children.

But when Abraham heard these words, he didn't question the Lord and ask, "Are you sure?"  Full of faith in the Lord, Abraham did as he was told.

This seems completely prophetic towards God's sacrifice of his own Son Jesus, a task that was taken to completion.  Because, as you know, as Abraham was about to plunge the knife into his son, Isaac, the Lord told Abraham that He now knew that Abraham had complete faith in Him.  In the end, God produced a ram and it was sacrificed in place of Isaac.

This may seem like such an extreme, but it simply shows the level of faithfulness in the Lord that Abraham had.