1033 We cannot be united with God unless we freely choose to love him. But we cannot love God if we sin gravely against him, against our neighbor or against ourselves: “He who does not love remains in death. Anyone who hates his brother is a murderer, and you know that no murderer has eternal life abiding in him.” Our Lord warns us that we shall be separated from him if we fail to meet the serious needs of the poor and the little ones who are his brethren. To die in mortal sin without repenting and accepting God’s merciful love means remaining separated from him for ever by our own free choice. This state of definitive self-exclusion from communion with God and the blessed is called “hell.”
1035 The teaching of the Church affirms the existence of hell and its eternity. Immediately after death the souls of those who die in a state of mortal sin descend into hell, where they suffer the punishments of hell, “eternal fire.”617 The chief punishment of hell is eternal separation from God, in whom alone man can possess the life and happiness for which he was created and for which he longs.
617 Cf. DS 76; 409; 411; 801; 858; 1002; 1351; 1575; Paul VI, CPG § 12.
Judas and perdition to “his own place”
24 And they prayed and said, “Lord, who knowest the hearts of all men, show which one of these two thou hast chosen 25 to take the place in this ministry and apostleship from which Judas turned aside, to go to his own place.”
Judas did not fight his “predominant fault”.
“Judas fell into impenitence through avarice, which he did not will to dominate; it led him to impenitence like a violent wind that hurls a ship on the rocks. — Reginald Garrigou-Lagrange O.P.
“…it is appointed for men to die once, and after this comes judgment”— Hebrews 9:27
Note: While it’s exact nature remains a mystery, Popes, Church Fathers, and theologians have in all centuries of the Catholic era commonly agreed on the reality of Hell, and explicitly taught that people who are indifferent to truth and incorrigible in wickedness do in fact risk going there. Sacred Scripture is explicit in warning. No Pope or Church Father has ever taught that Hell is “empty” or anything less than a mysterious fearful destiny reserved for those who “mock” His teachings.
Galatians 6:7 “Do not be deceived; God is not mocked, for whatsoever a man sows, that he will also reap”.
— Catholic apologist Trent Horn: on the reality of Hell
Catholic Critique 