The members of the Church may be divided into three classes:
1. Those who are still on the earth “having not here a lasting city, but seeking one that is to come” (Heb xiii. 14). They are referred to as the ‘Church Militant’ because they are still struggling with its three enemies; the world, the flesh and the devil.
2. Those who have reached the goal in Heaven; the Saints. They are referred to as the ‘Church Triumphant’ because they have already secured their victory.
3. Those who are expiating their sins in Purgatory. They are referred to as the ‘Church Suffering’ for the reason that they are still expiating their sins in the cleansing fire.
All are “fellow citizens with the saints and domestics of God”, working for the same object in union with God. The members of this great community are called “saints” because all are sanctified by Baptism (1 Cor. Vii.11) and are called to a holy life (1 Thess. Iv. 3). Those in Heaven have already attained perfect holiness. Yet St. Paul calls the Christians on earth “saints” (Eph. i. 1).
Catholics on earth, the souls in Purgatory and the blessed in Heaven are united with Christ, just as the members of a body are united with the head (Rom. Xii. 4). Christ is the head of the Christian body (Col. i. 18); He is the vine carrying strength and nourishment to the branches. Each member of the body has its own special functions; all members share the pain or pleasure felt by one part and the same is the case with the Communion of Saints. Catholics who have fallen into mortal sin are still members of the body, though dead members; they can regain life through confession and forgiveness of their sins but would cease to become members through excommunication if they were unfortunate enough to merit that censure.
All members of the Communion of Saints have a claim to share in the common goods of the Church, such as Masses, the means of grace, the prayers of the Church and all good done by individuals is for the benefit of all members. In the Our Father we pray for others as well as for ourselves; holy Mass is offered for the dead as well as the living; the same is true of the Office recited by the priest. Because of the Communion of Saints, there is more hope of converting the greatest sinner who still belongs to the Church than a Freemason who outwardly leads a good life but if cut off from the Communion of Saints; similarly, a Catholic can expect a quicker release from Purgatory than a non – Catholic. St. Francis Xavier always cheered himself by the thought that the Church was praying for him and supporting him with its good works. That the members of the body doing good even if other members do evil; can have a beneficial effect on the whole body is shown by the example that the entire city of Sodom would have been spared by God if there had been even ten good men found within its walls.
All Catholics can help each other by prayer and good works. St. Peter was freed from prison by the prayers of the Christians, “The prayer of St. Stephen” says St. Augustine, “procured the conversion of St. Paul.” The tears and prayer of St. Monica converted her son. In the old Testament, God promised that He would be merciful to the prayer of the priest (Lev. Iv, 20).
There is an obligation on living members of the Church to remember to pray and to do penance for those in Purgatory; who cannot help themselves. As a man’s debts can be paid off by the good intervention of another; so the debt of sin may be paid off by the good works, fasting, prayer and penance of others. The Jews of the Old Testament believed that help could be given to the souls of the departed; Judas Machabeus caused sacrifices to be offered for those who had fallen in battle; and sent money to the Temple for that purpose (2 Mach. xii). After the Consecration at holy Mass; there is a special petition prayer for the departed. St. Augustine said that “prayer is the key by which we open the gates of Heaven to the suffering souls”. The Council of Lyons in 1274 stated that the prayers of the living, especially holy Mass, almsdeeds and other works of piety are of great efficacy is lessening the suffering of the holy souls. The souls in Purgatory can also help us, though they cannot help themselves in the sense of speeding their exit from Purgatory and entry to Heaven. We should never forget our departed loved ones no those in general who perhaps have no one to pray for them. On the day of the Feast of All Souls (November 2nd), the Church remembers and prays for its members in Purgatory and makes it very easy for us to do the souls in Purgatory great good through the plenary indulgences available (once gained, a plenary indulgence is enough to remit all the suffering of a soul in Purgatory and free it to fly to God).
The saints in Heaven can also help us with their prayers before the throne of God (Apoc. Viii. 4) especially if we call upon them for help. They rejoice when a sinner is converted (Luke xv. 7). Their intercession has great efficacy, for the “continual prayer of a just man even on the earth availeth much” (Jas. V. 16). We see the power Abraham had with God when pleading for Sodom (Gen. xviii). “if” says St. Jerome, “the saints had such power when in the flesh, what can they not obtain for us now that they have secured their victory?” Our dead relatives and friends who are with God in Heaven, are always pleading for us at the throne of God and often save us from danger. “Charity never dies” says St. Paul (1 Cor. Xiii, 8) and the ties which bind us to those we love remain unbroken by death. The prophet Jeremias, and the holy high priest Onias, prayed in Limbo for the Jewish nation (2 Mach. xv. 14) and Christ promised His apostles that He would pray for them (John xiv. 16; 1 John ii, 1). Our Lady, the Mother of God is particularly powerful in releasing souls from Purgatory, on Saturdays, the day specially dedicated to Our Lady, she rescues many souls from Purgatory (John XXII, Sabbatine Bull). Nor are the holy angels indifferent to their future companions; one of the Church’s prayers speaks of St. Michael leading souls into Heaven. Our angel guardian, and the angels we have specially honoured on earth will pray for us in Purgatory.