3:1 {When we could no longer forbear} (mēketi stegontes). Stegō is old verb to cover from stegē, roof (Mr 2:4), to cover with silence, to conceal, to keep off, to endure as here and 1Co 9:12; 13:7. In the papyri in this sense (Moulton and Milligan's "Vocabulary"). Mēketi usual negative with participle in the "Koinē" rather than ouketi.
{We thought it good} (ēudokēsamen). Either literary plural as in 2:18 or Paul and Silas as more likely. If so, both Timothy and Silas came to Athens (Ac 17:15f.), but Timothy was sent ({we sent}, epempsamen, verse 2) right back to Thessalonica and later Paul sent Silas on to Beroea or Thessalonica (verse 5, {I sent}, epempsa). Then both Silas and Timothy came from Macedonia to Corinth (Ac 18:5).
{Alone} (monoi). Including Silas.
{God's minister} (diakonon tou theou). See on ¯Mt 22:13 for this interesting word, here in general sense not technical sense of deacon. Some MSS. have {fellow-worker} (sunergon). Already {apostle} in 2:7 and now {brother, minister} (and possibly {fellow-worker}).

3:3 {That no man be moved} (to mēdena sainesthai). Epexegetical articular infinitive in accusative case of general reference. Sainō is old word to wag the tail, to flatter, beguile and this sense suits here (only N.T. example). The sense of "moved" or troubled or disheartened is from siainesthai the reading of F G and found in the papyri.
{We are appointed} (keimetha). Present middle, used here as passive of tithēmi. We Christians are set {hereunto} (eis touto) to be beguiled by tribulations. We must resist.

3:4 {We told you beforehand} (proelegomen humin). Imperfect active, we used to tell you beforehand. Old verb, rare in N.T. (only in Paul).
{That we are to suffer persecution} (hoti mellomen thlibesthai). Mellō and present passive infinitive. Not mere prediction, but God's appointed will as it turned out in Thessalonica.

3:5 {That I might know} (eis to gnōnai). Paul's common idiom (verse 2), eis to and the infinitive of purpose (second aorist ingressive active of ginōskō, come to know).
{Lest by any means the tempter had tempted you} (mē pōs epeirasen humās ho peirazōn). Findlay takes this as a question with negative answer, but most likely negative final clause with mē pōs about a past action with aorist indicative according to the classic idiom as in Ga 2:2 (mē pōs--edramon) and Ga 4:11 after verb of fearing (Robertson, "Grammar", p. 988). It is a fear that the thing may turn out to be so about the past.
{Should be} (genētai). Here the usual construction appears (aorist subjunctive with mē pōs) about the future.

3:6 {Even now} (arti). Just now, Timothy having come (elthontos Timotheou, genitive absolute). Why Silas is not named is not clear, unless he had come from Beroea or elsewhere in Macedonia.
{Glad tidings of} (euaggelisamenou). First aorist middle participle of the verb for evangelizing (gospelizing). {Good remembrance} (mneian). Same word used by Paul 1:2. {Longing to see us} (epipothountes hēmās idein). Old and strong verb, epi-, directive, to long after. Mutual longing that pleased Paul ("we also you").

3:7 {Over you} (eph' humin). Epi with the locative, the basis on which the "comfort" rests.
{In} (epi). Locative case again with epi.
{Distress} (anagkēi).
{Physical necessity}, common sense in late Greek, choking (agchō, angor), and {crushing} trouble (thlipsis, thlibō).

3:8 {If ye stand fast} (ean humeis stēkete). Condition of first class, ean and present active indicative (correct text, not stēkēte subj.) of stēkō, late form from perfect hestēka of histēmi, to place.

3:9 {Render again unto God} (tōi theōi antapodounai). Second aorist active infinitive of double compound verb ant-apodidōmi, to give back (apo) in return for (anti). Old verb rare in N.T., but again in 2Th 1:6.
{For you} (peri humōn). Around (concerning) you, while in verse 2 huper (over is used for "concerning your faith."){For} (epi). Basis again as cause or ground for the joy.
{Wherewith we joy} (hēi chairomen). Probably cognate accusative hēn with chairomen attracted to locative charāi (Mt 2:10).

3:10 {Exceedingly} (huperekperissou). Double compound adverb, only in 1Th 3:10; 5:13 (some MSS. -ōs). Like piling Ossa on Pelion, perissōs, abundantly, ek perissou, out of bounds, huperekperissou, more than out of bounds (overflowing all bounds).
{And perfect} (kai katartisai). First aorist active articular infinitive of purpose (eis to idein--kai) of katartizō, to mend nets (Mt 4:21) or men (Ga 6:1) repair. Chiefly late.
{That which is lacking in} (ta husterēmata). The shortcomings, the lacks or left-overs (Col 1:24). From hustereō (husteron), to be late.

3:11 {Our God and Father himself} (autos ho theos kai patēr hēmōn). Note one article with both substantives for one person. {And our Lord Jesus} (kai ho Kurios hēmōn Iēsous). Separate article here with Iēsous. In Tit 2:13; 2Pe 1:1 only one article (not two) treating "our God and Saviour Jesus Christ" as one just like "our Lord and Saviour Jesus Christ" in 2Pe 1:11; 2:20; 3:18.
{Direct our way} (kateuthunai tēn hodon hēmōn). First aorist optative (acute accent on penult, not circumflex first aorist active infinitive) of kateuthunō, old verb to make straight path. Singular verb also, though both God and Christ mentioned as subject (unity in the Godhead). Apart from mē genoito ({may it not come to pass}) the optative in a wish of the third person is found in N.T. only in 1Th 3:11,12; 5:23; 2Th 2:17; 3:5,16; Ro 15:5,13.

3:12 {The Lord} (ho Kurios). The Lord Jesus. Paul prays to Christ.
{Make you to increase} (humas pleonasai). First aorist active optative (wish for future) of pleonazō, late verb from pleon (more), {to superabound}.
{And abound} (perisseusai). First aorist active optative (wish for future) of perisseuō from perissos, old verb, to be over (common in N.T.). It is hard to see much difference between the two verbs.

3:13 {To the end he may stablish} (eis to stērixai). Another example of eis and the articular infinitive of purpose. Same idiom in 3:2. From stērizō, from stērigx, a support. {Unblameable} (amemptous). Old compound adjective (a privative and verbal of memphomai, to blame). Rare in N.T. Predicate position here. Second coming of Christ again.