20 Yet there is no salvation for the world but in Christ: "For there is no other name under heaven given to men whereby we may be saved" ( Acts iv. 12). To Christ then we must return. At His feet we must prostrate ourselves to hear from His divine mouth the words of eternal life, for He alone can show us the way of regeneration, He alone teach us the truth, He alone restore life to us. It is He who has said: "I am the way, the truth, and the life" ( John xiv. 16). Men have once more attempted to work here below without Him, they have begun to build up the edifice after rejecting the corner stone, as the Apostle Peter rebuked the executioners of Jesus for doing. And lo! the pile that has been raised again crumbles and falls upon the heads of the builders, crushing them. But Jesus remains for ever the corner stone of human society, and again the truth becomes apparent that without Him there is no salvation: "This is the stone which has been rejected by you, the builders, and which has become the head of the corner, neither is there salvation in any other" ( Acts iv. 11, 12).
Source: Iucunda Sane (Vatican.va)