2 Maccabees 12:43-46: "And making a gathering, he sent twelve thousand drachms of silver to Jerusalem for sacrifice to be offered for the sins of the dead, thinking well and religiously concerning the resurrection, (For if he had not hoped that they that were slain should rise again, it would have seemed superfluous and vain to pray for the dead,) And because he considered that they who had fallen asleep with godliness, had great grace laid up for them. It is therefore a holy and wholesome thought to pray for the dead, that they may be loosed from sins."
Those who've died in a state of grace are not truly "dead"; they are our beloved in Heaven or in Purgatory (on their way to Heaven) and will forever be, world without end, part of the Communion of Saints -- the Church Triumphant (the Saints in Heaven, whether or not they are beatified or canonized), the Church Suffering (the holy souls in Purgatory), and the Church Militant (the faithful on earth). Because we can't know, aside from those the Church has beatified or canonized, who is already in Heaven, who is in Purgatory for a time, or who is damned, we pray for the dead for the rest of our lives -- assuming they are in Purgatory, while hoping they are in Heaven and not damned. We also ask those who've died to pray for us. While those whom the Church has deemed to be of the Church Triumphant (the canonized Saints) are in Heaven for certain and are, therefore, in no need of our prayers for them, we've always asked for them to pray for us. As to the Church Suffering in Purgatory, Aquinas teaches that they are not able to know, by themselves, our prayers; however, it is piously believed, and taught by St. Alphonsus Liguori, that God can make our prayers known to them - not directly, as they are deprived of the Beatific Vision until they enter Heaven, but by infusing this knowledge into their souls. St. Bellarmine teaches that because the Church Suffering is so close to God - much closer than we are and having the great consolation of knowing they are saved -- their prayers for us are very effective. So, as you pray for your dead loved ones, ask them to pray for you, too! As to the damned, there is no hope; no prayer can help them and we can't pray formally for those in Hell. The problem, of course, is that we can't know who is damned, and so we pray generally for "all the faithful departed."
For those who've died outside of visible Communion with Christ's Church or for those Catholics who've died seemingly without repentance and in scandal, public prayer cannot be offered, but we can most certainly still pray privately with the hope that they've died in a state of grace (i.e., those who are denied a Catholic funeral can't be prayed for liturgically, publicly, but they can most definitely be prayed for -- and should be prayed for -- privately). Priests can even offer Masses for such people privately, without naming them.
LITURGICAL PRAYER FOR THE DEAD
In addition to the prayers said just after death, and the prayers of the funeral Mass, it is Catholic practice to have Masses said for the departed on the 3rd, 7th, and 30th days after the death or burial, and also on the anniversaries of the death (or as close to it as possible). Masses for the dead have infinite value, in the objective order, for the souls of the departed. They also have great subjective value for those who survive in that it is comforting to know that Masses are being offered for one's departed loved ones. So, while the bereaved can arrange such Masses, others, even non-Catholics, can arrange with a priest to have such Masses
said, too, which would be a great gift of comfort to survivors.
Another thing to consider for yourself and your loved ones is to enroll in the Purgatorian Archconfraternity -- an organization for whose members, living or dead, Mass is offered. The Purgatorian Archconfraternity began with a group of Redemptorist Fathers in 1840, headquartered at the Church of S. Maria Monterone in Rome. Their group was raised by Pope Gregory XVI to the status of an Archconfraternity in 1841. After the Second Vatican Council, things went awry with the Archconfraternity as they did with everything else, but the Archconfraternity has been restored by the Transalpine Redemptorist Fathers who live in Golgotha Monastery (http://www.papastronsay.com/) on the little island of Papa Stronsay in Orkney, North of Scotland. Once enrolled in the Archconfraternity, the traditional Latin Mass will be offered for you or your loved ones, as members of the group, living or dead, every day (except for those days when only one priest is available, or on those days when no Masses are ever offered, such as Good Friday, etc.). The Rosary will be prayed each Monday for dead members. If a living member of the Archconfraternity dies, a special Mass will be offered for him as soon as the priests are notified. One may enroll for a year or for a lifetime, as a single individual or as a family (parents and children). Living members should also try to assist the souls in Purgatory through their prayers and works, especially through the Mass, and should spread this devotion to others, but no obligations bind one under the pain of sin.
The daily Masses and weekly Rosaries offered by the island priests will continue until Jesus comes again, God willing, as long as there are at least three priests on Papa Stronsay. If ever there were two priests, the Masses would be offered weekly. If there were to ever be one priest, obligations would cease -- but vocations are booming.
after Our Lady of the Rosary Library