for nothing: without a valid reason behind it, or without any real result from it
This is a common, everyday Greek adverb, not a special religious term. Its one core idea is the absence of a proper basis, and that absence can point in two directions: backward to the cause (there was no good reason for the thing) or forward to the result (the thing came to nothing).
In the New Testament every use is Paul's, apart from a single disputed appearance in Matthew, and Paul draws on both directions. When he says the governing authority does not carry the sword "for no reason" (Romans 13:4), or that a boastful teacher is "groundlessly" puffed up (Colossians 2:18), he means the thing has no valid ground behind it. When he fears he has "labored in vain" among the Galatians (Galatians 4:11), or warns the Corinthians they may have "believed in vain" (1 Corinthians 15:2), he means the thing may yield no lasting result.
The reader's main task is simply to notice which direction is in view, because English forces a choice between "without cause" and "in vain" that the one Greek word does not make. An older, classical shade of the word, acting "at random" or "thoughtlessly," stands in the background of both but does not surface plainly in the New Testament.
Nuances
Which sense the word carries in Colossians 2:18: "without cause, groundlessly" or "without due consideration, in a haphazard manner".
- majority"Without cause, groundlessly": the opponent's inflated self-importance rests on no real foundation.; James D. G. Dunn, The Epistles to the Colossians and to Philemon (NIGTC, 1996), 183-86; Douglas J. Moo, The Letters to the Colossians and to Philemon (Pillar, 2008), 225-27
- minority"Without due consideration, in a haphazard manner": the boasting is thoughtless rather than baseless.; Walter Bauer, Frederick W. Danker et al., A Greek-English Lexicon of the New Testament (BDAG), 3rd ed. (2000), 281
Whether the word belongs in the text of Matthew 5:22 at all.
- majorityIt is a later scribal addition that softens an absolute prohibition of anger, and should be omitted (the reading of the earliest Alexandrian witnesses).; Bruce M. Metzger, A Textual Commentary on the Greek New Testament, 2nd ed. (1994), 11
- minorityIt is original, since the external manuscript support is overwhelming and the pressure among early interpreters ran toward deleting it to bar anger entirely.; David Alan Black, 'Jesus on Anger: The Text of Matthew 5:22a Revisited,' Novum Testamentum 30 (1988): 1-8
Whether the word means "in vain, to no effect" or "without due consideration" in 1 Corinthians 15:2.
- majority"In vain, to no effect": their faith becomes empty if its content, Christ's resurrection, turns out to be false.; Gordon D. Fee, The First Epistle to the Corinthians (NICNT, 1987), 720-23
- minority"Without due consideration, in a haphazard manner": Paul concedes only that their initial faith may have been superficial, not that it will prove ineffective.; Anthony C. Thiselton, The First Epistle to the Corinthians (NIGTC, 2000), 1186-88