But He turned and said to Peter, “Get behind Me, Satan! You are an offense to Me, for you are not mindful of the things that are of God, but those that are of men.”

Matthew 16:23

There is more to be said in that last phrase you are not mindful of the things that are of God. Jesus was foretelling things that would soon take place. This is not the first time He spoke of this. Remember what Jesus said about Himself.

The Things of God

Just as Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in Him should not perish, but may have eternal life.

John 3:14–15

Jesus was speaking of this account from the Torah.

So the LORD sent poisonous serpents among the people, and they bit the people, and many children of Israel died. So the people came to Moses and said, “We have sinned for we have spoken against the LORD and against you. Pray to the LORD, and He will take away the serpents from us.” And Moses prayed for the people.
The LORD said to Moses, “Make a poisonous serpent, and put it on a pole, and it will be, that everyone who is bitten, when he looks at it, will live.” Moses made a bronze serpent and put it on a pole, and if a serpent had bitten any man, when he looked at the bronze serpent he lived.

Numbers 21:6–9

In that account, the Israelites had begun to complain and murmur against God’s provision. They refused to enter His rest (the Promised Land) and were remanded to wander in the wilderness of that sin. The circumstances of their present condition were of their own doing. Yet even in the midst of that wandering, God provided for their needs with manna from heaven.

God sent serpents to remind them of their precarious condition. They turned to God through Moses. Moses was instructed to make a likeness of the serpent from bronze, put it on a pole, and lift it up. Any who by faith, looked at the serpent to be healed of the poison would be cured and live. I can think that some in that multitude have thought that silly scheme and they perished. But to those who believed the declaration, they looked and lived.

It would be just like that for Jesus.

God made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him.

2 Corinthians 5:21

The sting of death is sin, and the strength of sin is the law.

1 Corinthians 15:56

Therefore as sin came into the world through one man and death through sin, so death has spread to all men, because all have sinned.

Romans 5:12

Just as the sting of the poisonous serpent would bring certain death, we know that we have an appointment with death by the sting of sin. The serpent was the source of the sting that brought death to the Israelis in the wilderness. Mortality in humanity that came as a result of the serpent was the source of the sting that brought death to all men.

Moses made an effigy of the serpent, he did not put a real serpent on that pole. In like manner, the same would happen to Jesus. It is not that Jesus was not a real human. On the cross, the Bible tells us that Jesus became sin for us. He was like us in death.

The precision in these foreshadows is breathtaking. I am not saying Jesus was not human, or that something magic happened. His death is real. And His death satisfied the justice due for sins. He unabashedly spoke of His death.

Again, Jesus said to them, “I am going away, and you will seek Me, and you will die in your sins. Where I am going, you cannot come.”
So the Jews said, “Will He kill Himself? For He said, ‘Where I am going, you cannot come.’ ”
He said to them, “You are from below; I am from above. You are of this world; I am not of this world. Therefore I said to you that you will die in your sins. For unless you believe that I am He, you will die in your sins.”
They said to Him, “Who are You?”
Jesus said to them, “Just who I have been telling you from the beginning. I have many things to say and to judge concerning you, but He who sent Me is true. So I tell the world what I heard from Him.”
They did not understand that He spoke to them of the Father. So Jesus said to them, “When you lift up the Son of Man, then you will know that I am He, and I do nothing of Myself. But I speak these things as My Father taught Me. He who sent Me is with Me. The Father has not left Me alone, for I always do those things that please Him.” As He spoke these words, many believed in Him.

John 8:21–30

He also hinted at something more than just His death, but that was something most could not comprehend. We must also consider all the words of Jesus. Peter was not mindful of the things that are of God. Namely that Jesus would give His life and take it back up again to prolong His days.

Lifted Up

Therefore My Father loves Me, because I lay down My life that I may take it up again. No one takes it from Me, but I lay it down Myself. I have power to lay it down, and I have power to take it up again. I received this command from My Father.”

John 10:17–18

This idea of being lifted up is also connected to what comes after His death. It is the destruction of the Gates of Hell. Resurrection would prolong His days, and then He would be received into heaven. That is, He is lifted up from this Earth. As His physical human advent on this planet careened to the culmination of the plan, death was not the end.

“Now My soul is troubled. What shall I say? ‘Father, save Me from this hour’? Instead, for this reason I came to this hour. Father, glorify Your name.”
Then a voice came from heaven, saying, “I have glorified it, and will glorify it again.” The crowd that stood by and heard it said that it had thundered. Others said, “An angel has spoken to Him.”
Jesus answered, “This voice came not for My sake, but for your sakes. Now judgment is upon this world. Now the ruler of this world will be cast out. And if I be lifted up from the earth, I will draw all men to Myself.” He said this to signify by what kind of death He would die.
The crowd answered Him, “We have heard from the law that the Christ remains forever. Why do You say, ‘The Son of Man must be lifted up’? Who is this Son of Man?”

John 12:27–34

Thankfully, we do not just look to a dead Christ on the cross to live. The cross is empty because He lives. We look to the living Jesus in glory. He signifies the hope that we have. He signifies our own resurrection. He takes the sting from death.

Any that would want to live, that is escape perdition, need only believe and put action to that faith by looking to Jesus for salvation.

Real Life After Death

Jesus spoke consistently of His death. It was also fitting in this location at the Grotto of Pan. He also spoke consistently of more to come after His death. It was His mission to die and experience death for everyone, believer or not. Through that death, He would bring many to glory. Any that would want it can have it.

But we see Jesus, who was made a little lower than the angels to suffer death, crowned with glory and honor, so that He, by the grace of God, should experience death for everyone.
For it was fitting for Him, for whom and by whom all things exist, in bringing many sons to glory, to make the Author of their salvation perfect through suffering.

Hebrews 2:9–10