Churches Militant, Penitent, and Triumphant
In some strains of Christian theology, the Christian Church may be divided into:the Church Militant, also called the Church Pilgrim, which consists of Christians on Earth who struggle as soldiers of Christ against sin, the devil, and "the rulers of the world of this darkness, against the spirits of wickedness in the high places";
the Church Penitent, also called the Church Suffering or the Church Expectant, which in the theology of certain churches, especially that of the Catholic Church, consists of those Christians currently in Purgatory; and
the Church Triumphant, which consists of those who have the beatific vision and are in Heaven.
The Church Militant and the Church Triumphant, fresco by Andrea da Firenze in Santa Maria Novella, c. 1365
Ecclesia militans, one of the largest icons in existence
The communion of saints, when referred to persons, is the spiritual union of the members of the Christian Church, living and the dead, but excluding the damned. They are all part of a single "mystical body", with Christ as the head, in which each member contributes to the good of all and shares in the welfare of all.
Revelation 5:8 presents the saints in heaven as linked by prayer with their fellow Christians on earth.