The "communion of saints" means that these three branches of the Church can help one another. We help the souls in Purgatory by our prayers and good works, and the saints in Heaven pray for us. But "communion of saints" means still more. Let us take an example. Suppose there are in a family, living together, a mother and three sons. The eldest son earns a large salary, the second son enough to support himself, and the youngest very little. They give their earnings to their mother, who from the combined amounts provides for the wants of all and draws from the large salary of the eldest to supply the needs of the youngest. Thus he who has too little for his support is--through his mother--aided by the one who has more than he needs. Now, the Church is our mother, and some of her children--the great saints--were rich in good works and did more than was necessary to gain Heaven, while others did not do enough. Then our mother, the Church, draws from the abundant satisfaction of her rich children to help those who are poor in merit and good works. The greatest treasure she has to draw from for that purpose is the more than abundant merits of Our Lord and the superabundant satisfaction of the Blessed Virgin and the greatest saints. Our Lord could have redeemed us all by the least suffering, and yet He suffered dreadful torments, and even shed His blood and died for us. The Blessed Virgin never sinned, yet she performed many good works and offered many prayers. Therefore "communion of saints" means, also, that we all share in the merits of Christ and in the superabundant satisfaction of the Blessed Virgin and of the saints; also in the prayers and good works of the Church and of her faithful and pious children. "The forgiveness of sins," i.e., by the Sacrament of Penance, through the power that God gave His priests; also by Baptism.