From then on Jesus began to show his disciples that he must go to Jerusalem and suffer much from the elders, the chief priests, and the scribes, be killed, and on the third day rise again.
In this verse Jesus, for the first time, begins to tell His disciples openly and directly about His coming sufferings, death, and resurrection. Until then He had hinted at it, but now, after Peter answered Jesus that he recognizes Him as the Son of God and the Christ, Jesus begins to reveal the true nature of His mission. He says that this is not a coincidence, but something that “must” happen according to God’s predetermined plan. Going to Jerusalem, being rejected by the religious authorities, suffering, death, and resurrection form the vital chain of the messianic mission. This passage shows that Jesus’ death and resurrection were not a tragedy, but God’s saving plan.