And so all the members of the Body are necessary to it, although in different ways and different degrees. Some, like pope and bishop, belong to its fundamental structure and are absolutely indispensable. They serve the outer and inner unity, the firm compactness and quiet stability, as well as the living fruitfulness of the Church. The other members, born of the superabundance of those powers of the Holy Spirit which vitalize the Body of Christ, serve its inward activity and movement. When we consider them all in the light of their ultimate purpose, we cannot arrange their functions in any precise order of rank and merit. “The head cannot say to the feet: I have no need of you. Yea, much more those that seem to be the more feeble members of the body, are more necessary” (1 Cor. xii, 21-22). And so it may happen that, though for the external history of the Body of Christ the activities of the structural organs, the official activities of pope or bishop, may be more manifest to the eye, yet the joyful poverty of a St. Francis of Assisi, the vigils of a St. Ignatius of Loyola and the charity of a St. Vincent de Paul may claim greater importance for its inner history, for the realization of the fullness of Christ.

Let us speak in the pages which follow of this constructive effectiveness of the “weaker” members of the Body of Christ. Let us see how and in what measure the rest of the faithful—and not only bishop and pope—work together for the building up of the Body of Christ; and in what degree the special gifts of the individual members benefit the whole organism.

The key to this matter is the doctrine of the “Communion of Saints.” By this doctrine the Church means a community of spirit and of spiritual goods among the saints on earth, that is among all those who are incorporated by faith and love in the one Head, Christ. More than that, she means also the vital communion of these faithful Christians with all those souls who have passed out of the world in the love of Christ, and who either as blessed souls enjoy in glory the Vision of their God, or as souls in the state of purgation await that Vision. The doctrine embraces therefore the whole mass of the redeemed, who in the various stages of development, as members of the militant, suffering or triumphant Church, are conjoined through their one Head, Jesus Christ, in one single family and fellowship, in one single sacred Body.