The Concept of Hell
Hell is a place or state in the afterlife reserved for unbelievers and Catholics who die unrepentant in a state of mortal sin. Forgoing repentance, the Catholic chooses to exclude himself from God and his grace. If he dies in this state, he is denied for eternity the vision of God and communion with the blessed.
In the New Testament, Jesus speaks of Gehenna and of the unquenchable fire, where those who refuse to believe or repent will be sent. Jesus declares that he will “send his angels, and they will collect … all who cause others to sin and all evildoers. They will throw them into the fiery furnace” (Matthew 13:41–42), and he then will condemn them by saying, “Depart from me, you accursed, into the eternal fire!” (Matthew 25:41). This vivid apocalyptic imagery is meant to dramatize the urgency of the Kingdom and the serious attitude toward salvation that Christians needed to have.
According to the Apostles' Creed, Jesus' own descent into Hell was to the underworld, Sheol, where he met those who had died before him, to share his victory over death. He died and stayed among the dead for a short time.
Is hellfire a literal fire?
The Church teaches that immediately after death, those who die in mortal sin descend into Hell, where they suffer eternal fire. There is not necessarily a literal fire. The chief punishment of hell is eternal separation from God, because only by seeing God can man possess the life and happiness for which he was created. Hell is self-annihilation: Rejection of God is the rejection of the state of being and the choosing of a condition of nonbeing.
The Church's teachings on Hell serve as a warning to man to make the best use of his time on earth. No one is predestined to go to Hell. It's an act of free will to choose mortal sin, to turn away from God, and to persist in that stance. The Missal contains prayers whereby the Church prays for the mercy of God, who wants all to repent. “Grant us your peace in this life, and save us from final damnation” (Roman Missal, EPI, Roman Canon, 88).