{We are bound} (opheilomen). Paul feels a sense of
obligation to keep on giving thanks to God (eucharistein t(9369)
the(9369), present infinitive with dative case) because of God's
continued blessings on the Thessalonians. He uses the same idiom
again in  2:13  and nowhere else in his thanksgivings. It is not
necessity (dei) that Paul here notes, but a sense of personal
obligation as in  1Jo 2:6  (Milligan). {Even as it is meet}
(kath(9373) axion estin). Opheilomen points to the divine,
axion to the human side of the obligation (Lightfoot), perhaps
to cheer the fainthearted in a possible letter to him in reply to
Paul's First Thessalonian epistle (Milligan). This adjective
axios is from ag(935c), to drag down the scales, and so weighty,
worthy, worthwhile, old word and appropriate here. {For that your
faith groweth exceedingly} (hoti huperauxanei h(8820)pistis hum(936e)).
Causal use of hoti referring to the obligation stated in
opheilomen. The verb huperauxan(935c) is one of Paul's frequent
compounds in huper (huper-bain(935c),  1Th 4:6 ; huper-ek-tein(935c),
 2Co 10:14 ; huper-en-tugchan(935c),  Ro 8:26 ; huper-nika(935c),  Ro
8:37 ; huper-pleonaz(935c),  1Ti 1:14 ) and occurs only here in N.T.
and rare elsewhere (Galen, Dio Cass.). Figure of the tree of
faith growing above (huper) measure. Cf. parable of Jesus about
faith-like a grain of mustard seed ( Mt 13:31f. ). {Aboundeth}
(pleonazei). Same verb in  1Th 3:12 , here a fulfilment of the
prayer made there. Milligan finds _diffusive_ growth of love in
this word because of "each one" (henos hekastou). Frame finds
in this fulfilment of the prayer of  1Th 3:12  one proof that II
Thessalonians is later than I Thessalonians.