Paul’s main concern in this section has been with secondary powers of evil, and more recently (v. 9) with Satan himself. Now he emphasizes that this whole struggle has its place in the purpose of God.

So (as the same Greek expression, translated differently, in 1 Thess. 2.13) refers backwards (contrast Jerusalem Bible), and has a rather general meaning. In order to find the right relation between verses 9-10 and 11-12, it is necessary to look at the wider context. Note first that verse 11 introduces, with the emphatic word God, a factor not mentioned directly since the end of chapter 1, namely, the activity of God. Most translations suggest that verse 9-10 give the reason for the events in verses 11-12, but when we read the passage as a whole, the reverse seems more natural, and is a quite possible meaning of the Greek. In verses 9-10, Paul has been describing events which will take place as the end approaches and (v. 10b) arrives. In verses 11-12, following his usual practice (see Diagram|fig:Table_2TH2-6.htm), he goes over some of the same ground again, but giving more detail and looking more deeply into the meaning of the events in question. If this is so, the translation should run: “The reason for this (that is, the events described in verses 9-10) is that God is sending a power of error….” Verse 11 would then unfold an aspect of the Christian “mystery” (cf. v. 7), explaining that the events of verses 9-10, summarized in verse 12, are the result of what God is doing.

The power which God sends has not been mentioned directly before, so following normal Greek usage in such cases, Paul does not use a definite article. This power leads unbelievers into error, in order that, or with the result that (the same problem as in v. 10), they will not only accept wrong information, but they will trust what is not worthy of trust. Cf. Moffatt “put faith in falsehood,” Phillips “put their faith in an utter fraud.” Paul uses here a definite article before “lie,” referring back to verse 9, where the “lie” (Good News Translation false) was mentioned for the first time, therefore without an article. The modern reader finds it easier to accept that the power of error produces the result that people believe what is false, rather than that God sends this power in order that people may believe what is false; but both concepts are included in the meaning, and the main clause God sends suggests the translation “in order that they may believe what is false.”

In linking verse 11 with verse 10, it is important that the conjunctive element (so or “therefore” or “for this reason”) refers to the various events of verses 8, 9, and 10, and not merely to the result or purpose suggested at the end of verse 10, namely, so as to be saved. It may, therefore, be important to introduce a transition in the form of “because of what is going to happen,” or “because of all that is going to happen.”

Since the activity of God in sending the power of error is something which has already begun to take place, it may be useful to use a verb form which suggests continuous activity, for example, “God is sending.”

It may be very difficult in some languages to speak of “sending the power of error,” since both “power” and “error” are abstracts, and they really qualify something else. It may even be impossible to speak of “sending” an abstract such as “power” or “error.” However, it may be possible to say “God causes them to think wrongly, and this strongly affects their thinking.” Or one may be able to say “God causes them to act very wrongly,” or “… to be badly mistaken in the way in which they act.”

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 .