ἄρα, an illative particle (akin, as it seems, to the verbal root 
ΑΡΩ to join, to be fitted [cf. Curtius, § 488; Vanicek, p. 47]), whose use among native Greeks is illustrated fully by Kühner, ii., §§ 509, 545; [Jelf, §§ 787-789], and 
Klotz ad Devar. ii., pp. 160-180, among others; [for a statement of diverse views see Bäumlein, Griech. Partikeln, p. 19f]. It intimates that, "under these circumstances something either is so or becomes so" (Klotz, the passage cited, p. 167): Latin 
igitur, 
consequently, [differing from 
οὖν in 'denoting a subjective impression rather than a positive conclusion.' Liddell and Scott (see 5 below)]. In the 
N. T. it is used frequently by Paul, but in the writings of John and in the so-called Catholic Epistles it does not occur. On its use in the 
N. T. cf. Winer's Grammar, §§ 53, 8 a. and 61, 6. It is found:
    
1. subjoined to another word: 
Romans 7:21; 
Romans 8:1; 
Galatians 3:7; 
ἐπεὶ ἄρα since, if it were otherwise, 
1 Corinthians 7:14; [
1 Corinthians 5:10, cf. Buttmann, § 149, 5]. When placed after pronouns and interrogative particles, it refers to a preceding assertion or fact, or even to something existing only in the mind: 
τίς ἄρα who then? Matthew 18:1 (i. e. one certainly will be the greater, 
who then?); 
Matthew 19:25 (i. e. certainly some will be saved; you say that the rich will not; 
who then?); 
Matthew 19:27; 
Matthew 24:45 (I bid you be ready; 
who then etc.? the question follows from this command of mine); 
Mark 4:41; 
Luke 1:66 (from all these things doubtless something follows; 
what, then?); 
Luke 8:25; 
Luke 12:42; 
Luke 22:23 (it will be one of us, 
which then?); 
Acts 12:18 (Peter has disappeared; 
what, then, has become of him?). 
εἰ ἄρα, 
Mark 11:13 (whether, since the tree had leaves, he might also find some fruit on it); 
Acts 7:1 [
Rec.] (
ἄρα equivalent to 'since the witnesses testify thus'); 
Acts 8:22 (if, since thy sin is so grievous, perhaps the thought etc.); 
εἴπερ ἄρα, 
1 Corinthians 15:15, (
אִם־נָא, 
εἰ ἄρα, 
Genesis 18:3). 
οὐκ ἄρα, 
Acts 21:38 (thou hast a knowledge of Greek; art thou not then the Egyptian, as I suspected?); 
μήτι ἄρα (Latin 
num igitur), did I then etc., 
2 Corinthians 1:17.
    
2. By a use doubtful in Greek writings (cf. Buttmann, 371 (318); [Winers Grammar, 558 (519)]) it is placed at the beginning of a sentence; 
and so, so then, accordingly, equivalent to 
ὥστε with a finite verb: 
ἄρα μαρτυρεῖτε [
μάρτυρές ἐστε T Tr WH], Luke 11:48 (
Matthew 23:31 ὥστε μαρτυρεῖτε); 
Romans 10:17; 
1 Corinthians 15:18; 
2 Corinthians 5:14 (
2 Corinthians 5:15) (in 
L T Tr WH no conditional protasis preceding); 
2 Corinthians 7:12; 
Galatians 4:31 (L T Tr WH διό); 
Hebrews 4:9.
    
3. in an apodosis, after a protasis with 
εἰ, in order to bring out what follows as a matter of course (German 
so ist ja the obvious inference is): 
Luke 11:20; 
Matthew 12:28; 
2 Corinthians 5:14 (
2 Corinthians 5:15) (R G, a protasis with 
εἰ preceding); 
Galatians 2:21; 
Galatians 3:29; 
Galatians 5:11; 
Hebrews 12:8; joined to another word, 
1 Corinthians 15:14.
    
4. with 
γέ, rendering it more pointed, 
ἄραγε [L Tr uniformly 
ἄρα γε; so R WH in 
Acts 17:27; cf. Winers Grammar, p. 45; 
Lipsius Gram. Untersuch., p. 123], 
surely then, so then (Latin 
itaque ergo): 
Matthew 7:20; 
Matthew 17:26; 
Acts 11:18 (L T Tr WH omit 
γέ); and subjoined to a word, 
Acts 17:27 [Winer's Grammar, 299 (281)].
    
5. ἄρα οὖν, a combination peculiar to Paul, at the beginning of a sentence (Winers Grammar, 445 (414); Buttmann, 371 (318) ["
ἄρα ad internam potius caussam spectat, 
οὖν magis ad externam." 
Klotz ad Devar. ii., p. 717; 
ἄρα is the more logical, 
οὖν the more formal connective; "
ἄρα is illative, 
οὖν continuative," Winers, the passage cited; cf. also Kühner, § 545, 3]) [
R. V.] 
so then (Latin 
hinc igitur): 
Romans 5:18; 
Romans 7:3, 
25; 
Romans 8:12; 
Romans 9:16, 
18; 
Romans 14:12 (L Tr omit WH brackets 
οὖν); 
Romans 14:19 [L marginal reading 
ἆρα]; 
Galatians 6:10; 
Ephesians 2:19; 
1 Thessalonians 5:6; 
2 Thessalonians 2:15.