I don’t know what kind of mood Paul was in when he wrote his second letter to the Thessalonians, but it is remarkable how many grammatical incongruities there are.
Read, for example, 2 Thess 2:7. Paul writes, τὸ γὰρ μυστήριον ἤδη ἐνεργεῖται τῆς ἀνομίας· μόνον ὁ κατέχων ἄρτι ἕως ἐκ μέσου γένηται. He has just said that something (τὸ κατέχον) — and will later say someone (ὁ κατέχων) — is restraining the coming of the antichrist. However, despite this restraint, the mystery of lawlessness (τὸ μυστήριον τῆς ἀνομίας) is already at work (ἤδη ἐνεργεῖται), a mystery that will some day (ἐν τῷ ἑαυτοῦ καιρῷ) give way to the obvious truth of who is behind the evil of our day.
The first “incongruity” is “the one who now holds it back (ὁ κατέχων) will continue to do so till he is taken out of the way” (ἄρτι ἕως ἐκ μέσου γένηται). I added the italics to show the NIV’s solution to the grammatical problem of ellipsis. You have to supply something after μόνον; it would have been nice if Paul had.
The NLT reads, “For this lawlessness is already at work secretly, and it will remain secret until the one who is holding it back steps out of the way.” Most versions have, “will do so” (NASB, ESV, HCSB, NET). The NRSV has, “but only until the one who now restrains it is removed.” But something has to be added, and these suggestions all work.
For me the real challenge is μόνον. Its meaning in context is clear; the working of evil will remain a mystery μόνον the restrainer gone. γένηται is middle, perhaps middle deponent, so an active (“steps out of the way,” NLT) or ambiguous (“is out of the way,” HCSB, ESV) translation is better than a passive, such as “ taken out of the way” (NASB, NET, NIV) or “is removed” (NRSV). By why μόνον?
μόνον is the neuter singular of μόνος used adverbially, and BDAG lists it under point 2a. “a marker of limitation, only, alone.” 2a is, “limiting the action or state to the one designated by the verb.” However, if you check the cross references (Mt 9:21; 14:36; Mk 5:36; Lk 8:50; 1 Cor 7:39; 15:19; Gal 1:23; Phil 1:27), none of them seem really parallel to our passage since they generally mean “only” or “alone.” So the use of μόνον in 2 Thess 2:6 is unique (except perhaps Gal 2:10). And troublesome.
Assuming μόνον is related in meaning to ὁ κατέχων as is suggested by word order, it all comes down to what verb has been assumed. μόνον can’t modify ὁ κατέχων directly since it is the wrong gender, so it is modifying an assumed verb and is adverbial. In other words, Paul is not saying that “only the Restainer is currently at work” as oppose to another person/force that could be at work.
Best says “but (‘only’, introducing a unique condition).” However, I can find no adversative meaning for μόνον in BDAG except in the correlative “not only, but also” (οὐ … μόνον ἀλλὰ καί).
Shogren says μόνον harks back to 2:6, which means the Restrainer is going to do what it/he is doing only until it/he is removed, suggesting (I assume) that the assumed verb is κατέχω.
Another way to say this is μόνον modifies ἄρτι. The one restraining does so “only until” (μόνον … ἄρτι) he is removed (see Bruce), which would mean an adverb is modifying another adverb.
Lightfoot (in Morris) says, “only it must work in secret, must be unrevealed, until he that restraineth now be taken out of the way.” This carries the sense of “however,” which keeps it in line with BDAG. In other words, μόνον introduces the limitation to the previous verbal expression — the Restrainer will do his work until removed.”
Like I said, I wonder what type of mood Paul was in when he wrote this. Either way, μόνον is an awkward word and it will be good to ask Paul what word or phrase he could have used if he wanted to be clearer.
I have lots of questions to ask when I get to heaven; this is #147.