It had to come to a head.  The discussions about Jesus were going on and on.  Many of the people loved Him, but the religious power-holders hated Him.  The idea that Jesus might become so popular that the Roman occupiers would blame the High Priest and ruling Council, threatened their position and reputation (John 11:48).

Caiaphas, the high priest at the time, was clearly angry.  He did not want any more discussion: he wanted Jesus to be dead.  Accusing the Sanhedrin Council of ignorance and failure to understand the implication of risking the wrath of the Roman Empire, he prophesied that it was better for one person to die than the whole nation should die (John 18:12-14).  Although the words came out of the High Priest's mouth, John commented that God was speaking.  Indeed, Jesus would die for all the Jews and also all the Gentiles, enabling those who believed to escape God's wrath and face eternity with no fear of eternal death or rejection.  

God can speak in any way and through any person.  If He can speak through a donkey (Numbers 22:21-38), He can certainly speak through an angry unbelieving Priest!  Of course, Caiaphas had not intended his words to be prophetic, but they were.  Even though he knew so much of the Old Testament writing, he did not understand that passages such as Isaiah 53:1-12 would be completely fulfilled when Jesus died for the sins of the world.
 
It is certainly true that we should not allow our anger to lead us into sin or distort the voice of God (Ephesians 4:26-27), but it is also true that God will work through the very worst of human anger so that people will praise Him (Psalm 76:10).  God always has the last word.  Although Caiaphas encouraged his religious team to find a way of killing Jesus, they were never able to get rid of Him; and God wove their deadly intrigue into His plan to save the world (Acts 2:23).  So, we should never think that human anger and violence will have the last word.  It will not.  God always has the last word.  Therefore do not be afraid.