It is precisely in the Passion, when the mercy of Christ is about to vanquish it, that sin most clearly manifests its violence and its many forms: unbelief, murderous hatred, shunning and mockery by the leaders and the people, Pilate's cowardice and the cruelty of the soldiers, Judas' betrayal - so bitter to Jesus, Peter's denial and the disciples' flight. However, at the very hour of darkness, the hour of the prince of this world, The sacrifice of Christ secretly becomes the source from which the forgiveness of our sins will pour forth inexhaustibly.
Source: Catechism of the Catholic Church (Vatican.va)