Maybe you will get a better picture that the devouring fire does annihilate from existence with these verses. Consume and devour gives a better connotation.
Isaiah 1:28
And the destruction of the transgressors and of the sinners shall be together, and they that forsake the Lord shall be
consumed.
Isaiah 5:24
Therefore as the fire devoureth the stubble, and the flame
consumeth the chaff, so their root shall be as rottenness, and their blossom shall go up as dust: because they have cast away the law of the Lord of hosts, and despised the word of the Holy One of Israel.
Isaiah 66:17
They that sanctify themselves, and purify themselves in the gardens behind one tree in the midst, eating swine's flesh, and the abomination, and the mouse, shall be
consumed together, saith the Lord.
Ezekiel 20:13
But the house of Israel rebelled against me in the wilderness: they walked not in my statutes, and they despised my judgments, which if a man do, he shall even live in them; and my sabbaths they greatly polluted: then I said, I would pour out my fury upon them in the wilderness, to
consume them.
Ezekiel 22:31
Therefore have I poured out mine indignation upon them; I have
consumed them with the fire of my wrath: their own way have I recompensed upon their heads, saith the Lord God.
Ezekiel 43:8
In their setting of their threshold by my thresholds, and their post by my posts, and the wall between me and them, they have even defiled my holy name by their abominations that they have committed: wherefore I have
consumed them in mine anger.
2 Thessalonians 2:8
And then shall that Wicked be revealed, whom the Lord shall
consume with the spirit of his mouth, and shall destroy with the brightness of his coming:
Do you know who is being spoken of and what is their fate?
Ezekiel 28:18
Thou hast defiled thy sanctuaries by the multitude of thine iniquities, by the iniquity of thy traffick; therefore will I bring forth a fire from the midst of thee, it shall devour thee, and I will bring thee to
ashes upon the earth in the sight of all them that behold thee.
Malachi 4:3
And ye shall tread down the wicked; for they shall be
ashes under the soles of your feet in the day that I shall do this, saith the Lord of hosts.
Ashes... another indication of the fate of those who are consumed by fire. Nothing but ashes left. No existence after the fire is finished. It is the example of Sodom and Gomorrha
2 Peter 2:6
And turning the cities of Sodom and Gomorrha into
ashes condemned them with an overthrow, making them an ensample unto those that after should live ungodly;
The people of Sodom and Gomorrha are not living in a lake of fire, they are not still in a state of being burned. They are consumed and nothing but ashes. No life, no existence. The resurrection is the only life after death.