CATECHISM OF THE CATHOLIC CHURCH
SECOND EDITION

Paragraphs 650–653

650 The Fathers contemplate the Resurrection from the perspective of the divine person of Christ who remained united to his soul and body, even when these were separated from each other by death: "By the unity of the divine nature, which remains present in each of the two components of man, these are reunited. For as death is produced by the separation of the human components, so Resurrection is achieved by the union of the two."
651 "If Christ has not been raised, then our preaching is in vain and your faith is in vain." The Resurrection above all constitutes the confirmation of all Christ's works and teachings. All truths, even those most inaccessible to human reason, find their justification if Christ by his Resurrection has given the definitive proof of his divine authority, which he had promised.
652 Christ's Resurrection is the fulfillment of the promises both of the Old Testament and of Jesus himself during his earthly life. The phrase "in accordance with the Scriptures" indicates that Christ's Resurrection fulfilled these predictions.
653 The truth of Jesus' divinity is confirmed by his Resurrection. He had said: "When you have lifted up the Son of man, then you will know that I am he." The Resurrection of the crucified one shows that he was truly "I AM", the Son of God and God himself. So St. Paul could declare to the Jews: "What God promised to the fathers, this he has fulfilled to us their children by raising Jesus; as also it is written in the second psalm, 'You are my Son, today I have begotten you.'" Christ's Resurrection is closely linked to the Incarnation of God's Son, and is its fulfillment in accordance with God's eternal plan.