"We bring you the good news that what God promised to the fathers, this day he has fulfilled to us their children by raising Jesus." The Resurrection of Jesus is the crowning truth of our faith in Christ, a faith believed and lived as the central truth by the first Christian community; handed on as fundamental by Tradition; established by the documents of the New Testament; and preached as an essential part of the Paschal mystery along with the cross:
Christ is risen from the dead!
Dying, he conquered death;
To the dead, he has given life.
Source: Catechism of the Catholic Church (Vatican.va)