The grave isn’t fiery. And yet hell is referred to as such many times. It is also referred to as being eternal punishment.
Mat 5:22 But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire.
Mat 5:29 And if thy right eye offend thee, pluck it out, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.
Mat 5:30 And if thy right hand offend thee, cut it off, and cast it from thee: for it is profitable for thee that one of thy members should perish, and not that thy whole body should be cast into hell.
Mat 10:28 And fear not them which kill the body, but are not able to kill the soul: but rather fear him which is able to destroy both soul and body in hell.
Mat 11:23 And thou, Capernaum, which art exalted unto heaven, shalt be brought down to hell: for if the mighty works, which have been done in thee, had been done in Sodom, it would have remained until this day.
Mat 16:18 And I say also unto thee, That thou art Peter, and upon this rock I will build my church; and the gates of hell shall not prevail against it.
Mat 18:9 And if thine eye offend thee, pluck it out, and cast it from thee: it is better for thee to enter into life with one eye, rather than having two eyes to be cast into hell fire.
Mat 23:15 Woe unto you, scribes and Pharisees, hypocrites! for ye compass sea and land to make one proselyte, and when he is made, ye make him twofold more the child of hell than yourselves.
Mat 23:33 Ye serpents, ye generation of vipers, how can ye escape the damnation of hell?
Mar 9:43 And if thy hand offend thee, cut it off: it is better for thee to enter into life maimed, than having two hands to go into hell, into the fire that never shall be quenched:
Mar 9:45 And if thy foot offend thee, cut it off: it is better for thee to enter halt into life, than having two feet to be cast into hell, into the fire that never shall be quenched:
Mar 9:47 And if thine eye offend thee, pluck it out: it is better for thee to enter into the kingdom of God with one eye, than having two eyes to be cast into hell fire:
Luk 10:15 And thou, Capernaum, which art exalted to heaven, shalt be thrust down to hell.
Luk 12:5 But I will forewarn you whom ye shall fear: Fear him, which after he hath killed hath power to cast into hell; yea, I say unto you, Fear him.
Luk 16:23 And in hell he lift up his eyes, being in torments, and seeth Abraham afar off, and Lazarus in his bosom.
Act 2:27 Because thou wilt not leave my soul in hell, neither wilt thou suffer thine Holy One to see corruption.
Act 2:31 He seeing this before spake of the resurrection of Christ, that his soul was not left in hell, neither his flesh did see corruption.
Jas 3:6 And the tongue is a fire, a world of iniquity: so is the tongue among our members, that it defileth the whole body, and setteth on fire the course of nature; and it is set on fire of hell.
2Pe 2:4 For if God spared not the angels that sinned, but cast them down to hell, and delivered them into chains of darkness, to be reserved unto judgment;
Rev 1:18 I am he that liveth, and was dead; and, behold, I am alive for evermore, Amen; and have the keys of hell and of death.
Rev 6:8 And I looked, and behold a pale horse: and his name that sat on him was Death, and Hell followed with him. And power was given unto them over the fourth part of the earth, to kill with sword, and with hunger, and with death, and with the beasts of the earth.
Rev 20:13 And the sea gave up the dead which were in it; and death and hell delivered up the dead which were in them: and they were judged every man according to their works.
Rev 20:14 And death and hell were cast into the lake of fire. This is the second death.
This is every verse that speaks of hell in the New Testament. This is my final authority. For all matters. We can let people decide for themselves. What is your final authority on this matter? Can you honestly say all of these references are to the grave? You would have to shoehorn the definition and allegorize greatly.
Your “final authority” uses a word that is not in the Septuagint nor in the Masoretic text nor Dead Sea Scrolls, nor is it in any of the greek writings that make up the source of our new testament.
The lost do perish, as is clear in John 3:16, and the wages of sin is death, as is clear in Romans 6:23, but nowhere in the bible does it say that lost human beings suffer for all eternity. It’s only inference that leads people there.
Remember, when Jesus words are interpreted “hell”, he is really saying Gehenna. It’s a real place. It was a place of death - by fire - but death. And it is possible that the consuming fire is God, himself. Note, also, the dictionary definition of consume or consuming, and then, as Ecclesiastes 12:7 states “...and the spirit returns to God who gave it.
The gospel of Jesus is GOOD news. It is telling the lost that they can live forever with him. He is not telling them that if they don’t it will be worse than any human being could ever imagine. That’s not the message.
The message is to accept his free gift and live in eternity in his presence, or perish, die, be destroyed - in a word - end.
And that “punishment” will be eternal.