The Roman Catholic Church does not teach its people to have confidence in the full forgiveness of their sins through the death of Christ alone. Nor are they taught that the righteousness of God accomplished by Jesus Christ is their permanent possession. The result is that the faithful Catholic is taught never to come to full assurance of salvation during their earthly life, for they are still capable of committing “mortal sin.” A Catholic's redemption is always dependent on their maintaining a faithfulness to the Church's doctrine and practice.
Thus Catholics are taught that when they die, if they have not committed mortal sins (and with the exception of the special class of believers they call “saints”), all go to the place the church calls purgatory. The Catechism states, "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…"
"The Church formulated her doctrine of faith on Purgatory especially at the Councils of Florence and Trent" (Catechism 1030-1031). This concept of purgatory led to the unbiblical Catholic doctrine of prayers for the dead (Catechism 1032). Catholic believers are taught that "it is a holy and a wholesome thought to pray for the dead that they may be loosed from their sins" (Catechism 958).