Furnace

Keller's chapter, The Obedient Master (Encounters With Jesus), explores the accounts of the Lord Jesus' agony in the Garden of Gethsemane. I would really recommend reading the whole chapter. It has really helped me to understand in a much deeper way than before what Jesus choose to suffer and how much he suffered. Here's part of what Keller says:

Here in the dark, with the disciples asleep, when Jesus could very easily slip away, the Father lets him know what he is in for. As Jonathan Edwards says in his "Christ's Agony" sermon, "It was the first time that Christ had a full view of the difficulty of this command; which appeared so great as to cause that bloody sweat." And so, when he goes to the cross for us after this experience in the garden, he goes with vivid firsthand knowledge of what will happen. And that makes Jesus' action the greatest act of love to the Father- and to his fellow human beings- in the history of the world. No one ever faced suffering like this in order to love, and so no one ever loved like this. Edwards continues:

'The agony of Jesus Christ was caused by a vivid, bright, full, immediate view of the wrath of God. God the Father, as it were, set the cup down before him, which was vastly more terrible than Nebuchadnezzar's furnace. He now had a near view of the furnace into which he was about to be cast. He stood and viewed the raging flames and the glowings of its heat that he might know where he was going and what he was a out to suffer. He felt what Ezekiel said, "You shall drink the cup of ruin and desolation and tear your breasts." He felt what Isaiah said, that you will "drink the cup of his wrath...the bowl of staggering." Christ was going to be cast into a dreadful furnace of wrath and it was not proper that he should plunge himself into it blindfolded as not knowing how dreadful the furnace was. Therefore God brought him and set him at the mouth of the furnace that he might look in and stand and view its fierce and raging flames and might see where he was going and might voluntarily enter into it and bear it for us, knowing what it was. If Jesus Christ did not full know before he took it, and drunk it, it would not properly have been his own act as a human being. But when he took that cup knowing what he did, so was his love to us infinitely more wonderful and his obedience to God infinitely more perfect.'

God set the cup in front of Jesus, as it were, and let him smell it and taste it when it was still possible for Jesus to pull away and protect himself. In effect, the Father was saying, "Here's the cup that you are about to drink. Here is the furnace into which you are about to be cast. See these friends of yours sleeping over there? If they are to be saved, there is no other way. Either they perish, or you perish. See how terrible the heat is, see what pain and anguish you must endure. Is your love for them and for me so great that you will go on and take it?"

...Jesus said to God, "Thy will be done." Edwards concludes, "His sorrows abounded, but his love did much more abound. Christ's soul was overwhelmed with a deluge of grief, but this was from a deluge of love to sinners in his heart sufficient to overflow the world, and overwhelm the highest mountains of its sins. Those great drops of blood that fell down to the ground were a manifestation of an ocean of love in Christ's heart."