2 Thessalonians 1:6

⁴ So that we ourselves glory in you in the churches of God for your patience and faith in all your persecutions and tribulations that ye endure:

⁵ Which is a manifest token of the righteous judgment of God, that ye may be counted worthy of the kingdom of God, for which ye also suffer:

Seeing it is a righteous thing with God to recompense tribulation to them that trouble you;

⁷ And to you who are troubled rest with us, when the Lord Jesus shall be revealed from heaven with his mighty angels,

⁸ In flaming fire taking vengeance on them that know not God, and that obey not the gospel of our Lord Jesus Christ:

Do read the surrounding verses too, because the context often says more than a single verse.

Compare

BSB: After all, it is only right for God to repay with affliction those who afflict you,
KJV: Seeing it is a righteous thing with God to recompense tribulation to them that trouble you;
WEB: For it is a righteous thing with God to repay affliction to those who afflict you,
ASV: if so be that it is righteous thing with God to recompense affliction to them that afflict you,
DARBY: if at least [it is a] righteous thing with God to render tribulation to those that trouble you,
BLB: For indeed [it is] righteous with God to repay those oppressing you⁺ with tribulation,

ÅB: så sant det er rettferdig for Gud å gi dem som trenger dere, trengsel til vederlag,
OTB: For det er rettferdig for Gud å bringe trengsel over dem som plager dere,
B1930: så sant det er rettferdig for Gud å gi dem som trenger eder, trengsel til vederlag,

Colossians 3:25
But he that doeth wrong shall receive for the wrong which he hath done: and there is no respect of persons.
Read in context
Zechariah 2:8
For thus saith the LORD of hosts; After the glory hath he sent me unto the nations which spoiled you: for he that toucheth you toucheth the apple of his eye.
Read in context
Deuteronomy 32:41–43
If I whet my glittering sword, and mine hand take hold on judgment; I will render vengeance to mine enemies, and will reward them that hate me.
Read in context
Exodus 23:22
But if thou shalt indeed obey his voice, and do all that I speak; then I will be an enemy unto thine enemies, and an adversary unto thine adversaries.
Read in context
Psalms 94:20–23
Shall the throne of iniquity have fellowship with thee, which frameth mischief by a law?
Read in context
Psalms 74:22–23
Arise, O God, plead thine own cause: remember how the foolish man reproacheth thee daily.
Read in context
Isaiah 49:26
And I will feed them that oppress thee with their own flesh; and they shall be drunken with their own blood, as with sweet wine: and all flesh shall know that I the LORD am thy Saviour and thy Redeemer, the mighty One of Jacob.
Read in context
Revelation 6:10
And they cried with a loud voice, saying, How long, O Lord, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth?
Read in context