The overall importance of missionary work is a part of the teachings in the Ad Gentes document. It is here where the greatest need is required. The document speaks to how missionary work is vital to part of the Christian conception of the good:
Yet man must respond to God Who calls, and that in such a way, that without taking counsel with flesh and blood (Gal. 1:16), he devotes himself wholly to the work of the Gospel. This response, however can only be given when the Holy Spirit gives His inspiration and His power.
In this, the development of a base for which modern missionaries can be reared and fostered represents one of the greatest needs for Christianity. The document speaks to how missionaries need to be fostered more, developed in greater stock and fiber. In doing so, how this can be facilitated by the Catholic Church, as an institution, and as Catholics, as individual parishioners, becomes the most pressing need that emerges from the decree.