Rev. 20:14-15, "And death and hell were cast into the lake of fire. This is the second death. And whosoever was not found written in the book of life was cast into the lake of fire."
Rev. 21:8, "But the fearful, and unbelieving, and the abominable, and murderers, and whoremongers, and sorcerers, and idolaters, and all liars, shall have their part in the lake which burneth with fire and brimstone: which is the second death."
Symbolic.
The "First" death then, is the physical death that each person dies on this earth - a physical, but TEMPORARY death from which everyone will be resurrected. Those who are righteous will be resurrected to everlasting life and those who are wicked will be resurrected for the judgment and the "Second Death", believed by nearly ALL to be a physical death also, but this time the death is presumed to be PERMANENT!
The "second death" means "dead to sin" so only the sin dies while the person lives free of their sins.
Verses = "dead to sin" and "he that is dead is freed from sin" and "Being then made free from sin" and "the wages of sin is death" and more per link here = Romans 6
The "Lake of fire" causes death to sin = 1 Corinthians 3:15 "If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire."
So the person is being "SAVED" by the "FIRE" and not hurt by it.
Just to flesh out your unique brand of theology, if everyone is saved, what was the purpose of Christ coming to earth and then dying on the cross?