The progressive revelation of the Resurrection
The Pharisees and many of the Lord's contemporaries hoped for the resurrection. Jesus teaches it firmly. To the Sadducees who deny it he answers, "Is not this why you are wrong, that you know neither the scriptures nor the power of God?" Faith in the resurrection rests on faith in God who "is not God of the dead, but of the living."
Source: Catechism of the Catholic Church (Vatican.va)