Matters of "life or death" are faced often enough, emergency response teams train and practice to respond to situations in order to save lives. What we need is a training for allowing death to replace life. The story of death for life begins way back in the book of Genesis.
I. Story Of Death
A. Lamb for a man
The theme of the innocent suffering for the guilty begins, as does Israel's love affair with blood and death.
B. Lamb for a family
Exodus 12:3 (quickview)  Speak ye unto all the congregation of Israel, saying, In the tenth [day] of this month they shall take to them every man a lamb, according to the house of [their] fathers, a lamb for an house: And if the household be too little for the lamb, let him and his neighbour next unto his house take [it] according to the number of the souls; every man according to his eating shall make your count for the lamb. Your lamb shall be without blemish, a male of the first year: ye shall take [it] out from the sheep, or from the goats: And ye shall keep it up until the fourteenth day of the same month: and the whole assembly of the congregation of Israel shall kill it in the evening. And they shall take of the blood, and strike [it] on the two side posts and on the upper door post of the houses, wherein they shall eat it.
C. Lamb for a nation
Leviticus 16:18 (quickview)  And he shall go out unto the altar that [is] before the LORD, and make an atonement for it; and shall take of the blood of the bullock, and of the blood of the goat, and put [it] upon the horns of the altar round about.
II. First the physical, then the Spiritual
A. Jesus didn't want people to die physically when He said
B. Teaching self-denial deny (cessation - to disavow)
C. Jesus followers were taught save\lose... lose\save death for life
Mark 8:35 (quickview)  For whosoever will save his life shall lose it; but whosoever shall lose his life for my sake and the gospel's, the same shall save it. For what shall it profit a man, if he shall gain the whole world, and lose his own soul? Or what shall a man give in exchange for his soul?
D. Jesus begins to talk about eating His flesh and drinking His blood ... and people split
E. Jesus talks about death, but notice Peter's words
III. Same attitude
A. Lamb for a world... Jesus firstfruits
B. His death physical ours Spiritual