"Hell exists. Christ has said so.
It matters little that unbelievers deny it. In spite of this denial, its existence is a terrible reality. But it is convenient that we advance a little further and try to discover what is in it.
The Catechism, that little book containing a marvelous summary of Catholic doctrine, tells us that hell is "the sum of all evils, without any mixture of good".
Wonderful definition. But there is another, even more profound form: the one left to us in the Gospel by Our Lord Jesus Christ himself. It is the same phrase that He will pronounce on the Day of Judgment: "Depart from Me, you cursed, go into eternal fire". In this terrible formula is contained a marvelous summary of the whole theology of hell".
Fr. Royo Marín/Catholicity Blog