2 Thessalonians 1:8

(MLV) in flames of fire, giving vengeance to those who do not know God and to those who do not obey the good-news of our Lord Jesus Christ,
(KJV)
In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:

(1611 KJV) In flaming fire, taking vengeance on them that know not God, and that obey not the Gospel of our Lorde Iesus Christ,
(1587 Geneva Bible) In flaming fire, rendring vengeance vnto them, that doe not know God, and which obey not vnto the Gospel of our Lord Iesus Christ,
(1526 Tyndale) in flammynge fyre rendrynge vengeaunce vnto them that knowe not God and to them that obeye not vnto the gospell of oure Lorde Iesus Christ

Counterfeit Versions
(1881 RV) in flaming fire, rendering vengeance to them that know not God, and to them that obey not the gospel of our Lord Jesus:
(1901 ASV) rendering vengeance to them that know not God, and to them that obey not the gospel of our Lord Jesus:
(AMP) To deal out retribution (chastisement and vengeance) upon those who do not know or perceive or become acquainted with God, and [upon those] who ignore and refuse to obey the Gospel of our Lord Jesus Christ.
(CEB) He will give justice with blazing fire to those who don’t recognize God and don’t obey the good news of our Lord Jesus.
(CEV) and with a flaming fire. Our Lord Jesus will punish anyone who doesn’t know God and won’t obey his message.
(ERV) He will come with burning fire to punish those who don’t know God—those who refuse to accept the Good News about our Lord Jesus.
(ESV) in flaming fire, inflicting vengeance on those who do not know God and on those who do not obey the gospel of our Lord Jesus.
(GNB) with a flaming fire, to punish those who reject God and who do not obey the Good News about our Lord Jesus.
(HCSB) taking vengeance with flaming fire on those who don’t know God and on those who don’t obey the gospel of our Lord Jesus.
(LB) bringing judgment on those who do not wish to know God and who refuse to accept his plan to save them through our Lord Jesus Christ.
(PHILLIPS) It will bring full justice in dazzling flame upon those who have refused to know God or to obey the Gospel of our Lord Jesus Christ.
(THE MESSAGE) When the Master Jesus appears out of heaven in a blaze of fire with his strong angels, he’ll even up the score by settling accounts with those who gave you such a bad time.
(NASV) dealing out retribution to those who do not know God and to those who do not obey the gospel of our Lord Jesus.
(NCV) Then he will punish those who do not know God and who do not obey the Good News about our Lord Jesus Christ.
(NET) With flaming fire he will mete out punishment on those who do not know God and do not obey the gospel of our Lord Jesus.
(NIRV) He will punish those who don’t know God. He will punish those who don’t obey the good news about our Lord Jesus.
(NIV) He will punish those who do not know God and do not obey the gospel of our Lord Jesus.
(NLV) He will punish those who do not know God and those who do not obey the Good News of our Lord Jesus Christ.
(NLT) in flaming fire, bringing judgment on those who don’t know God and on those who refuse to obey the Good News of our Lord Jesus.
(RSV) inflicting vengeance upon those who do not know God and upon those who do not obey the gospel of our Lord Jesus.
(VOICE) On that day—when the clouds draw back displaying His powerful heavenly messengers in a fiery blaze, Jesus the Lord will appear from heaven dealing out perfect justice to anyone who doesn’t know God and anyone who disobeys the good news of our Lord Jesus.
(NAB-Roman Catholic) in blazing fire, inflicting punishment on those who do not acknowledge God and on those who do not obey the gospel of our Lord Jesus.
(NWT-Jehovah’s Witnesses) in a flaming fire, as he brings vengeance on those who do not know God and those who do not obey the good news about our Lord Jesus.

Textus Receptus - Traditional Text
ἐν πυρὶ φλογός, διδόντος ἐκδίκησιν τοῖς μὴ εἰδόσι Θεὸν, καὶ τοῖς μὴ ὑπακούουσι τῷ εὐαγγελίῳ τοῦ Κυρίου ἡμῶν Ἰησοῦ Χριστοῦ·

Hort-Westcott - Critical Text
εν πυριs φλογοσ διδοντοσ εκδικησιν τοισ μη ειδοσιν θεον και τοισ μη υπακουουσιν τω ευαγγελιω του κυριου ημων ιησου

Corrupted Manuscripts
This verse is corrupted in the following manuscripts:

Changes “Flaming Fire” to “retribution”
B 03 - Vaticanus - Fourth century
D 06 - Paris: Claromontanus - Sixth century
F 010 - Ninth century
G 012 - Ninth century
Psi 044 - Eight/Ninth/ century
2464 - (Minuscule) - Ninth century

Removes “Christ” after Jesus
B 03 - Vaticanus - Fourth century
D 06 - Paris: Claromontanus - Sixth century
K 018 - Ninth century
L 020 - Ninth century
P 025 - Ninth century
X 033 - Tenth century

Manuscripts which agree with the Textus Receptus for this Verse

Keeps “In flaming fire”
Byzantine Text (450-1450 A.D.)
Aleph 01 - Sinaiticus - Fourth century
A 02 - Alexandrinus - Fifth century
0111 - Seventh century

Keeps Christ” after Jesus
Byzantine Text (450-1450 A.D.)
Aleph 01 - Sinaiticus - Fourth century
A 02 - Alexandrinus - Fifth century

Published Critical Greek Texts with Corruptions
Reads “in a flame of fire” or “retribution”
Lachmann, Karl - 1842
Tregelles, Samuel - 1857
Wordsworth, Christopher - 1856 revised in 1870

Omit “Christ” after Jesus
Lachmann, Karl - 1842
Tischendorf, Constantine - 1869
Tregelles, Samuel - 1857
Alford, Henry - 1849 revised in 1871
Westcott and Hort - 1881
Nestle - 1927 as revised in seventeenth edition in 1941
Nestle-Aland - 1979 - Twenty Sixth Edition
Nestle-Aland - 1993 - Twenty Seventh Edition
United Bible Societies - 1983 - Fourth Edition
Weiss, Bernhard - 1894
Von Soden, Freiherr - 1902

Affected Teaching
This verse received the ax twice from its detractors. First some of the modern versions remove the reality that Hell is going to be a place of eternal fire. The modern versions want to make it sound like a place of only justice without severe and eternal consequences for sin. The second ax hit the title of the Lord Jesus Christ by removing “Christ” which is His title of Deity.