Many disbelieve in hell. They put it out of their minds, in part because it puts a brake on their activities. This is foolish, since wishing hell away does nothing positive, as the early Christians knew. It's a real state, and real people end up there.
Ignatius of Antioch
"Corrupters of families will not inherit the kingdom of God. And if they who do these things according to the flesh suffer death, how much more if a man corrupt by evil teaching the faith of God, for the sake of which Jesus Christ was crucified? A man become so foul will depart into unquenchable fire; and so will anyone who listens to him" (Epistle to the Ephesians 16:1-2 [A.D. 110]).
The Martyrdom of St. Polycarp
"Fixing their minds on the grace of Christ, [the martyrs] despised worldly tortures and purchased eternal life with but a single hour. To them, the fire of their cruel torturers was cold. They kept before their eyes their escape from the eternal and unquenchable fire" (2:3 [A.D. 155]).
Epistle to Diognetus
"When you know what is the true life, that of heaven; when you despise the merely apparent death, which is temporal; when you fear the death which is real, and which is reserved for those who will be condemned to the everlasting fire, the fire which will punish even to the end those who are delivered to it, then you will condemn the deceit and error of the world" (10:7 [inter A.D. 125/200]).
The Second Epistle of Clement
"If we do the will of Christ, we shall obtain rest; but if not, if we neglect his commandments, nothing will rescue us from eternal punishment (5:5 [A.D. 150]).
"No more is it possible for the evil-doer, the avaricious, and the treacherous to hide from God than it is for the virtuous. Every man will receive the eternal punishment or reward which his actions deserve. Indeed, if all men recognized this, no one would choose evil even for a short time, knowing that he would incur the eternal sentence of fire. On the contrary, he would take every means to control himself and to adorn himself with virtue, so that he might obtain the good gifts of God and escape the punishments" (The First Apology 12 [A.D. 148]).
"We have been taught that only they may aim at immortality who have lived a holy and virtuous life near to God. We believe that they who lve wickedly and do not repent will be punished in everlasting fire" (First Apology 21).
"[Jesus] shall come from the heavens in glory with his angelic host, when he shall raise the bodies of all the men who ever lived. Then he will clothe the worthy in immortality; but the wicked, clothed in eternal sensibility, he will commit to the eternal fire, along with the evil demons" (First Apology 52).
Theophilus of Antioch
"Give studious attention to the prophetic writings [the Bible] and they will lead you on a clearer path to escape the eternal punishments and to obtain the eternal good things of God….[God] will examine everything and will judge justly, granting recompense to each according to merit. To those who seek immortality by the patient exercise of good works, he will give everlasting life, joy, peace, rest, and all good things….For the unbelievers and for the contemptuous, and for those who do not submit to the truth but assent to iniquity, when they have been involved in adulteries, and fornications, and homosexualities, and avarice, and in lawless idolatries, there will be wrath and indignation, tribulation and anguish; and in the end, such men as these will be detained in everlasting fire" (Ad Autolycus 1:14 [A.D. 181]).
"The penalty increases for those who do not believe the Word of god and despise his coming….[I]t is not merely temporal, but eternal. To whomsoever the Lord shall say, 'Depart from me, accursed ones, into the everlasting fire,' they will be damned forever" (Against Heresies 4:28:2).
"[God will] send the spiritual forces of wickedness, and the angels who transgressed and became apostates, and the impious, unjust, lawless, and b.asphemous among men into everlasting fire" (Against Heresies 1:10:1 [A.D. 180]).
"After the present age is ended he will judge his worshipers for a reward of eternal life and the godless for a fire equally perpetual and unending" (Apology 18:3 [A.D. 197]).
"Oh, what a day that will be, and how great when it comes, dearest brethren. When the Lord…[will] cast into hell evildoers and will condemn our persecutors to the eternal fire and to punishing flame" (Epistle to the People of Thibar 58:10 [A.D. 253]).