The Communion of Saints (communo sanctorum, a fellowship of, or with, the saints). The doctrine expressed in the second clause of the ninth article in the received text of the Apostles' Creed: "I believe . . . the HolyCatholicChurch, the Communion of Saints".
"The communion of saints is the spiritual solidarity which binds together the faithful on earth, the souls in purgatory, and the saints in heaven in the organic unity of the same mystical body under Christ its head, ..." - Catholic Encyclopedia