Purgatory and Hell
From the Catechism of the Catholic Church, Simplified
Those Purified (1030-1032)
Those who die in God's grace but are not yet perfectly purified are guaranteed eternal salvation. They undergo purification after death to gain the holiness needed to enter heaven.
This "Purgatory" (Councils of Florence and Trent) is totally different from the punishment of the damned. It is a cleansing fire. "The person will be saved, but only through fire" (1 Cor 3:15). "As for certain lesser faults, there is a purifying fire" (Pope St. Gregory the Great).
The Church has always prayed for the dead and offered Mass for them. Judas Maccabees "made atonement for the dead that they might be freed from their sins" (1 Macc 12:46). "Let us not hesitate to help those who have died and to offer our prayers for them" (St. John Chrysostom).
Hell - Final Separation from God (1033)
We are united to God only if we freely choose to love him. We cannot love God if we sin gravely against him, our neighbor or ourselves. "He who does not love, remains in death" (1 Jn 3:14). Jesus warns us that we could be separated from him if we fail to help the poor in their serious needs (Mt 25:31-46). To die in unrepented mortal sin separates us from God forever by our own free choice. This self-exclusion from God's presence is called "hell."
Jesus' Teaching (1034)
Jesus spoke of hell. "It is better to lose one of your members than to have your whole body thrown into Gehenna" (Mt 5:29). "Be afraid of the one who can destroy both body and soul in Gehenna" (Mt 10:28). Jesus will send his angels who "will gather all evil doers and throw them into the furnace of fire" (Mt 13:41-42). Jesus will say to some, "Depart from me, you cursed, into the eternal fire" (Mt 25:41).
The Church Teaching (1035-1036)
The Church teaches that hell exists and that those who die in mortal sin will suffer "eternal fire." This means a definitive separation from God (who alone is man's happiness).
These teachings on hell call man to use his freedom in view of his eternity. "Enter by the narrow gate; for the gate is wide and the way is easy, that leads to destruction." This call is urgent because "those who find it are few" (Mt 7:13-14). "Since we do not know the day nor the hour we should watch constantly" (Second Vatican Council).
No One Predestined to Hell (1037)
God predestines no one to hell (Council of Trent). Damnation comes about only by a persistence in mortal sin until death. God wants "all to come to repentance" (2 Pet 3:9). The Church prays "save us from final damnation and count us among those you have chosen" (Roman Canon).