What is the Catholic belief about purgatory?

Answer 1

The Council of Trent set forth the Catholic belief on Purgatory as such:

"The Catholic Church, by the teaching of the Holy Spirit, in accordance with Sacred Scripture and the ancient tradition of the Fathers, has taught in the holy councils, and most recently in this ecumenical council, that there is a purgatory (can.30), and that the souls detained there are helped by the prayers of the faithful, and especially by the acceptable Sacrifice of the Altar (can.3)..."

The word "Purgatory" is sometimes understood as a place, an intermediate state between heaven and hell. Properly speaking, Purgatory is the condition of souls which, at the moment of death, are in the state of grace but which have not completely expiated their faults, nor attained the degree of purity necessary to enjoy the vision of God.

Purgatory is therefore temporary, and after a soul has been purified there, it goes to Heaven. It is not a trial where merit may be gained or lost, but a a state of atonement and expiation. Once dead, the time of merit and God's mercy is over for a soul, and only God's judgment remains. God will not condemn a soul in grace, however, He can not permit anything defiled in heaven, thus, if a soul in grace has yet to fulfill in justice some debt of temporal punishment, it does so now.

The Church, however, considers the Mystical Body of Christ to be composed of both those living in grace on Earth and those who have died in grace. Physical death does not cut off the faithful soul from this communion. Therefore, the Church teaches that souls in Purgatory may be assisted by the prayers and penances of the faithful, and especially benefit from the Holy Mass. The soul, in return, will surely be a patron of those who have helped it during its time in purgatory.

Roman Catholic AnswerThe Final Purification, or Purgatory

1030 All who die in God's grace and friendship, but still imperfectly purified, are indeed assured of their eternal salvation; but after death they undergo purification, so as to achieve the holiness necessary to enter the joy of heaven.

1031 the church gives the name Purgatory to this final purification of the elect, which is entirely different from the punishment of the damned. (Cf. Council of Florence (1439): Denzinger 1304; Council of Trent (1563): Denzinger 1820; (1547): 1580; see also Benedict XII, Benedictus Deus (1336): Denzinger 1000) The Church formulated her doctrine of faith on Purgatory especially at the Councils of Florence and Trent. the tradition of the Church, by reference to certain texts of Scripture, speaks of cleansing fire: (Cf. 1 Cor 3:15; 1 Pet 1:7.)

As for certain lesser faults, we must believe that, before the Final Judgment, there is a purifying fire. He who is truth says that whoever utters blasphemy against the Holy Spirit will be pardoned neither in this age nor in the age to come. From this sentence we understand that certain offenses can be forgiven in this age, but certain others in the age to come. (St. Gregory the Great, Dial. 4, 29: J.P. Migne, ed., Patrologia Graeca {Paris, 1857-1866} 77, 396; cf. Mt 12:31.)

1032 This teaching is also based on the practice of prayer for the dead, already mentioned in Sacred Scripture: "Therefore [Juda Maccabeus] made atonement for the dead, that they might be delivered from their sin." (2 Macc 12:46.) From the beginning the Church has honored the memory of the dead and offered prayers in suffrage for them, above all the Eucharistic sacrifice, so that, thus purified, they may attain the beatific vision of god. (Cf. Council of Lyons II (1274): Denzinger 856) The Church also commends almsgiving, indulgences, and works of penance undertaken on behalf of the dead:

Let us help and commemorate them. If Job's sons were purified by their father's sacrifice, why would we doubt that our offerings for the dead bring them some consolation? Let us not hesitate to help those who have3 died and to offer our prayers for them. (St. John Chrysostom, Hom. in 1 Cor. 41, 5: J.P. Migne, ed., Patrologia Graeca {Paris, 1857-1866} 61, 361; cf. Job 1:5

from The Catechism of the Catholic Church, second edition, English translation 1994