This scene is not only the prelude to the crucifixion, but also the resurrection. Jesus talks about the perfume preparing him for death, but he also talks about drinking new wine in the Kingdom. You cannot have one without the other, because this is God's whole plan. The redemption of mankind is critical in the crucifixion, but not just so we will have eternal insurance. It is also important because the new Kingdom where Jesus will once again drink with us is the final plan of God.