From that time Jesus began to show to His disciples that He must go to Jerusalem, and suffer many things from the elders and chief priests and scribes, and be killed, and be raised the third day.
22 Then Peter took Him aside and began to rebuke Him, saying, “Far be it from You, Lord; this shall not happen to You!”
23 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 of God, but the things of men.” — Matthew 16:21-23.
Jesus then begins to clearly or openly tell His disciples about the reality of sufferings, death, and resurrection that await Him. He is preparing their minds for these events so that they are not shocked or are better prepared to handle them when they happen. He tells them about the resurrection by way of assurance so that they may not lose heart. He rebukes Peter seriously when he tells Jesus there will be no suffering or death.