Traduction œcuménique de la Bible begins a new section here and New English Bible a new paragraph, but this verse is closely linked with verse 5, repeating and partly expanding it. It is true that there is a distinction, for Paul’s main concern is moving away from the situation of the Thessalonians to general teaching about the last days. But the two subjects are not separated, and there are references to “you” in verses 7 and 10.
The Greek begins with a word meaning “since” or “if it is true that.” It is like the “if” in the sentence “If there is such a thing as justice, John will come to a bad end,” which strongly implies that there is justice in the world, and that therefore John will come to a bad end. Most translations replace the “if” by an emphatic statement, e.g. Bible de Jérusalem “for it will indeed be the effect of God’s justice to render tribulation to those who inflict it on you.”
Good News Translation‘s God will do what is right is followed by a colon which points that reader (though not necessarily the listener) forward to the second part of the sentence. In this way a logical relation is implied. The punishment of the persecutors and the relief (v. 7) of those who suffer unjustly now are examples or consequences of the fact that God will do what is right. The literal meaning of the Greek is “since (it is) just with God.” Good News Translation‘s restructuring reflects the fact that it is fundamental to biblical teaching (1) that God is just, and (2) that his justice or righteousness expresses itself in action, in doing what is right.
God will do what is right is expressed in many languages as “God will do what he should.” A modal element such as “should” suggests correctness of action. However, it is important to relate this directly to what follows, and therefore in some languages the following clause is introduced by a conjunction such as “for”; for example, “God will do what he should, for he will bring suffering on those who made you suffer.” In other languages it may be more appropriate to translate “God will do what is right. That means he will bring suffering…”
He will bring suffering on those who make you suffer is literally “to pay back trouble to those who trouble you.” “Pay back” is an emphatic word which suggests a reciprocal action such as giving in return. In 1 Thess. 3.9 Paul uses the same word in speaking about giving thanks. Good News Translation leaves the reciprocal action to be understood, as it clearly can be, from the context. Suffering and suffer suggest in Greek some crushing pressure or oppression, either on the body or on the mind. Paul does not specify which, but probably both are included.
It is often impossible to say he will bring suffering, but a causative expression is almost always appropriate, for example, “those who make you suffer he will cause to suffer in return.” By introducing some such expression as “in return,” one may emphasize the reciprocal factor suggested by the Greek text itself. The reciprocal activity may, however, be merely implied, for example, “he will cause to suffer those who cause you to suffer.”
Quoted with permission from Ellingworth, Paul and Nida, Eugene A. A Handbook on Paul’s Second Letter to the Thessalonians. (UBS Handbook Series). New York: UBS, 1976. For this and other handbooks for translators see here .