This is called a translation error. This is only because the scribes did not have all the information we now possess in trying to understand the bible. They correctly translated the preposition as for, however the context is all wrong, and only by comparing scripture to scripture do we learn that this verse is more accurately translated as to ever and ever, which signifies an end, rather than for ever and ever which signifies infinity.
KJV
Rev 20:10 And the devil, who deceived them, was cast into the lake of fire and brimstone where the beast and the false prophet are. And they will be tormented day and night **for [to]*ever and ever.
*This verse has been mistranslated, where it reads 'for’ever and ever, it should read 'to’ever and ever. Implying duration through a time, as opposed to infinite time.
*Root from (Greek) : εἰς
Transliteration: eis
Part of Speech: preposition.
Definitions: into, unto, to, towards, for, among.
Lexicon: eis, a Prep. Governing the Accusative, and denoting entrance into, or direction and limit: into, to, towards, for, among. ie: duration through a time; of the time in which a thing is done.
We can know that this is correct because as we listen to the bible, we get harmony, and so the context is that the lake of fire is the second death, which signifies a complete end
Rev 20:14 Then Death and Hades were cast into the lake of fire. This is the second death.
1Cor 15:26 The last enemy that will be destroyed is death.
Rev 20:15 And anyone not found written in the Book of Life was cast into the lake of fire.
Rev 21:8 "But the cowardly, unbelieving, abominable, murderers, sexually immoral, sorcerers, idolaters, and all liars shall have their part in the lake which burns with fire and brimstone, which is the second death.
Thus we can be assured that the verse is correctly translated as “to” ever and ever, because the second death is the final death and that signifies a complete end. Rather, we can understand this as the final day and night here on earth. which is to’ ever. because the last day is the end of time, which is the end of day and night and time and so on that day the lake of fire swallows up the remaining sin in the universe and God creates a new heaven and earth
Another translation error common in all bibles is the use of the word messenger and angel.
Angle and messenger is the same word
However in some cases, the word angel should have been translated as messenger but again the information they had, meaning the understanding they had, was not as complete then as it is now.
Christ is a messenger, man is a messenger, an angel is a messenger. All messengers of the good news
However, Christ is not an angel, man is not an angel, and an angel is not a man, and an angel is not Christ, yet the common word messenger is accurate for all.
When the bible teaches about a “chief messenger or archangel” well this isn’t speaking of an angel, such as Michael the archangel, This is speaking of Christ, because Christ is the chief messenger of the good news. for example in the book of Jude
1:9 (King James Version)
Yet Michael the archangel, when contending with the devil he disputed about the body of Moses, durst not bring against him a railing accusation, but said, The Lord rebuke thee.
This is speaking of Christ, Michael is another name for Christ in this context. And we can know this is true because nobody is above Christ, and a archangel would be the chief angel, and sense no angel is above another angel, we know that the top, the chief, the leader, the king, the ONE TRUE messenger is always Christ.
Well this is a bible translation error. And we can be assured of it because we also have the original in which to compare the translation to. As well as the Strongs or Youngs concordance to define archaic words to us.