While Israel was not expecting a crucified messiah, the holy Spirit guided the disciples to understand the importance of the cross in God’s plan after the fact. Equally surprising was the disciples’ own encounter with the cross. Without the death to sin accomplished by being “crucified with Christ”, as St. Paul put it, there is no resurrection to life.
He summoned the crowd with his disciples and said to them, “Whoever wishes to come after me must deny himself, take up his cross, and follow me. For whoever wishes to save his life will lose it, but whoever loses his life for my sake and that of the gospel will save it. What profit is there for one to gain the whole world and forfeit his life? What could one give in exchange for his life? Whoever is ashamed of me and of my words in this faithless and sinful generation, the Son of Man will be ashamed of when he comes in his Father’s glory with the holy angels.”