60 To apply the remedies thus briefly indicated to the task of saving the world as We have traced it above, Jesus Christ, our Divine King, has chosen priests as the first-line ministers and messengers of His gospel. Theirs is the duty, assigned to them by a special vocation, under the direction of their Bishops and in filial obedience to the Vicar of Christ on earth, of keeping alight in the world the torch of Faith, and of filling the hearts of the Faithful with that supernatural trust which has aided the Church to fight and win so many other battles in the name of Christ: "This is the victory which overcometh the world, our Faith."
Source: Divini Redemptoris (Vatican.va)