God's message to us is unmistakable: Life is tenuous. The time for mercy and forgiveness is now. When Christ comes again, at the end of history, it will be as a just judge who separates the good from the wicked. The righteous will experience the Beatific Vision in Heaven. The lost will burn forever in the unquenchable fire that is Hell.
Since many today deny Hell's existence, it is worth remembering that during these apparitions, both Sister Lucy and St. Faustina witnessed Hell first hand and wrote about its horrors. At Fatima, Mary told Lucy, Jacinta and Francisco that many people go to Hell because they have no one to pray or make sacrifices on their behalf. She then showed the children a glimpse of Hell which Sr. Lucy describes in her book, Memoirs:
[Mary] opened Her hands once more, as She had done the two previous months. The rays [of light] appeared to penetrate the earth, and we saw, as it were, a vast sea of fire. Plunged in this fire, we saw the demons and the souls [of the damned]. The latter were like transparent burning embers, all blackened or burnished bronze, having human forms. They were floating about in that conflagration, now raised into the air by the flames which issued from within themselves, together with great clouds of smoke. Now they fell back on every side like sparks in huge fires, without weight or equilibrium, amid shrieks and groans of pain and despair, which horrified us and made us tremble with fright (it must have been this sight which caused me to cry out, as people say they heard me). The demons were distinguished [from the souls of the damned] by their terrifying and repellent likeness to frightful and unknown animals, black and transparent like burning coals. That vision only lasted for a moment, thanks to our good Heavenly Mother, Who at the first apparition had promised to take us to Heaven. Without that, I think that we would have died of terror and fear.Throughout her life, Sister Faustina Kowalska, a barely literate, Polish nun, received visions of Christ, during which our Lord instructed her. Faustina recorded these conversations in her diary, later published as: The Diary of Saint Maria Faustina Kowalska: Divine Mercy in My Soul. Here, St. Faustina recounts her experience of Hell and graphically details the various unending torments inflicted on the damned:
Today, I was led by an angel to the chasm of hell. It is a place of great torture; how awesomely large and extensive it is! The kinds of tortures that I saw; the first torture that constitutes hell is the loss of God; the second is perpetual remorse of conscience; the third is that one's condition will never change; the fourth is the fire that will penetrate the soul without destroying it — a terrible suffering, since 8it is a purely spiritual fire, lit by God's anger; the fifth torture is continual darkness, and a terrible, suffocating smell, and despite the darkness, the devil and the souls of the damned see each other and all the evil, both of others and of their own; the sixth torture is the constant company of Satan; the seventh torture is horrible despair, hatred of God, vile words, curses and blasphemies. These are the tortures suffered by all the damned together, but that is not the end of their sufferings.
There are special tortures destined for particular souls. These are the torments of the senses. Each soul undergoes terrible and indescribable sufferings, related to the manner in which it has sinned. There are caverns and pits of torture where one form of agony differs from another. I would have died at the very sight of these tortures if the omnipotence of God had not supported me. Let the sinner know that he will be tortured throughout all eternity, in those senses which he made use of to sin. I am writing this at the command of God, so that no soul may find an excuse by saying there is no hell, or that nobody has ever been there, and so no one can say what it is like.The Church affirms the existence of Hell, its eternity and nature [i.e., the chief pain of Hell is one's separation from God; there are also physical privations in addition to spiritual death]. It does not describe eternal damnation in detail. The visions of Sr. Lucy and St. Faustina are private revelations, not the infallible Word of God. Nonetheless, the accounts of these heroic women of faith cannot be dismissed. Those who ignore such testimony do so at their own peril. Ultimately, it is our decision to sin or to love that determines whether we spend eternity in Hell. God respects our free will, even if we chose perdition over Him.