144 Certainly there is the greatest need now of such valiant soldiers of Christ who will work with all their strength to keep the human family safe from the dire ruin into which it would be plunged were the teachings of the Gospel to be flouted, and that order of things permitted to prevail which tramples underfoot no less the laws of nature than those of God. The Church of Christ, built upon an unshakable rock, has nothing to fear for herself, as she knows for a certainty that the gates of hell shall never prevail against her. Rather, she knows full well, through the experience of many centuries, that she is wont to come forth from the most violent storms stronger than ever and adorned with new triumphs. Yet her maternal heart cannot but be moved by the countless evils with which so many thousands would be afflicted during storms of this kind, and above all by the consequent enormous injury to spiritual life which would work eternal ruin to so many souls redeemed by the Blood of Jesus Christ.
Source: Quadragesimo Anno (Vatican.va)