Eternal, conscious, literal, fiery hell is historical.

Antioch's letter To the Ephesians (117AD)
"such a one shall go in his foulness to the unquenchable fire" (16:2).

Epistle to Diognetus (138AD)
"when you fear the death which is real, which is kept for those that shall be condemned to the everlasting fire, which shall punish up to the end those that were delivered to it. Then you will marvel at those who endure for th sake of righteousness the fire which is for a season" (10:7-8).

2 Clement (150AD)
"Nothing shall rescue us from eternal punishment, if we neglect His commandments (6:7).

"...when they see those who have done amiss, and denied Jesus by word or deed, are punished with terrible torture in unquenchable fire" (17:7).

The Martyrdom of Polycarp (156-60AD)
"And the fire of their cruel torturers had no heat for them, for they set before their eyes an escape from the fire which is everlasting and never quenched" (2:3).

"You threaten with the fire that burns for a time, and is quickly quenched, for you do not know the fire which awaits the wicked in the judgment to come and in everlasting punishment" (11:2).

Jesus (c.30 AD)
"If your hand or your foot causes you to stumble, cut it off and throw it from you; it is better for you to enter life crippled or lame, than to have two hands or two feet and be cast into the eternal fire" (Matt 18:8).