John Chrysostom

This is no small subject of enquiry which we propose, but rather about things which are of the first necessity and which all men enquire about; namely, whether hell fire have any end. For that it hath no end Christ indeed declared when he said, "Their fire shall not be quenched, and their worm shall not die."

...As I said then; that it hath no end, Christ has declared. Paul also saith, in pointing out the eternity of the punishment, that the sinners "shall pay the penalty of destruction, and that for ever." And again, "Be not deceived; neither fornicators, nor adulterers, nor effeminate, shall inherit the the kingdom of God." And also unto the Hebrews he saith, "Follow peace with all men, and the sanctification without which no man shall see the Lord." And Christ also, to those who said, "In thy Name we have done many wonderful works," saith, "Depart from Me, I know you not, ye workers of iniquity." And the virgins too who were shut out, entered in no more. And also about those who gave Him no food, He saith, "They shall go away into everlasting punishment."