64 It is especially your task, as We have already pointed out, to encourage the faithful and arouse in them such zeal in this cause that they will share the solicitudes of the entire Church and will readily lend an ear to the Lord's word, commanding, as of old, so in every age: "Go forth from thy land and thy kindred, and from the house of thy father, and come into a land which I shall show thee."
Source: Fidei Donum (Vatican.va)