New International Version
God is just: He will pay back trouble to those who trouble you

American Standard Version
if so be that it is righteous thing with God to recompense affliction to them that afflict you,

Berean Study Bible
After all, it is only right for God to repay with affliction those who afflict you,

Douay-Rheims Bible
Seeing it is a just thing with God to repay tribulation to them that trouble you:

English Revised Version
if so be that it is a righteous thing with God to recompense affliction to them that afflict you,

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

World English Bible
Since it is a righteous thing with God to repay affliction to those who afflict you,

Young's Literal Translation
since it is a righteous thing with God to give back to those troubling you -- trouble,

2 Thessalonians 1:6 Additional Translations ...