I was blown away the first time I realized that Isaac knew exactly what was going on. After all he grew up watching his father make animal sacrifices. True, he asks where the sacrifice will come from but that still leaves him lying on that altar watching his father brandish the knife over him without any recorded protest. How's that for obedience and trust? What I didn't realize until reading it yesterday was that Isaac's significance goes far beyond underscoring trust. He is a "type," a forerunner of Christ, as In Conversation with God points out. Very cool.
Origen points out that the sacrifice of Isaac makes us more clearly understand the mystery of the Redemption. "The fact that Isaac was compelled to carry the wood for the holocaust is a figure of Christ who was made to carry his cross on his shoulders. But at the same time, carrying the wood for the holocaust is the task of a priest. So Isaac was both victim and priest... Christ is at one and the same time Victim and High Priest. Indeed, according to the spirit, He offers the victim to his Father; according to the flesh, He himself is offered on the altar of the Cross. In Conversation with God, Vol. 4 (Origen, Homilies on the Book of Genesis, 8, 6, 9)]