COMMUNION OF SAINTS. The unity and co-operation of the members of the Church on earth with those in heaven and in purgatory. They are united as being one Mystical Body of Christ. The faithful on earth are in communion with each other by professing the same faith, obeying the same authority, and assisting each other with their prayers and good works. They are in communion with the saints in heaven by honoring them as glorified members of the Church, invoking their prayers and aid, and striving to imitate their virtues. They are in communion with the souls in purgatory by helping them with their prayers and good works.