The basic meanings correspond to the nuances imparted by the preposition, “to take before,” “to anticipate.” In the NT the use is along the second of these two lines.
1. “To anticipate,” 1 C. 11:21; also Mk. 14:8: Jesus interprets the anointing, which the woman intended as an act of grateful reverence, as an intimation of His imminent death. Since He sees ahead His death as a malefactor, and realises that His disciples will abandon Him, it is not to be expected that any should anoint Him as an act of piety. The saying could hardly have been invented, and this is an argument in favour of the authenticity of sayings which express His expectation of death (→ II, 24, 949).
2. “To surprise,” Gl. 6:1: The point of the προλημφθῇ is that Paul has in view a fault into which the brother is betrayed “unawares,” so that it is not intentionally wrong. In this case brotherly help is demanded rather than unloving judgment (→ I, 176). There must be readiness to share the burden of offences before God (vv. 1–5 are closely interrelated, so that in v. 4 Paul emphasises that the readiness to find an excuse, indicated by προλημφθῇ, is to extend only to the fault of the brother, not to one’s own).
. Vol. 4: Theological Dictionary of the New Testament. 1964- (G. Kittel, G. W. Bromiley & G. Friedrich, Ed.) (electronic ed.) (14–15). Grand Rapids, MI: Eerdmans.
That brings us to a consideration of the word translated “overtaken.” The context which we have presented will help us in determining the meaning of the word as it is used here. The word is prolambanō (προλαμβανω). It has the following meanings: “to anticipate, to forecast, to overtake, to come upon, to take unawares.” Two of our Greek authorities, Lightfoot and Alford, think that the reference here is to the act of a Christian detecting a fellow-Christian in the commission of a sin, thus catching him unawares in it, and establishing by that means the fact of the sin. Four, Burton, Vincent, Expositors, and Meyer think that it refers to the Christian himself being overtaken by the sin before he is aware that he has done wrong. Robertson merely defines the word without interpreting it. The context rules in favor of the opinion of the four. Vincent says, “surprised by the fault itself.” Expositors says, “His surprise in the very act.”Wuest, K. S. (1997). Wuest's Word Studies from the Greek New Testament : For the English Reader (Ga 6:1). Grand Rapids: Eerdmans.
1. Overtaken in a fault (προλημφθῇ — ἔν τινι παραπτώματι). The verb means lit. to take before; to anticipate or forestall. Elsewhere only Mk. 14:8; 1 Cor. 11:21. LXX, Wisd. 18:17. Not, be detected in the act by some one else before he can escape, but surprised by the fault itself; hurried into error. Thus πρὸ has the sense of before he is aware, and ἐν is instrumental, by.* For fault or trespass, see on Matt. 6:14.
Vincent, M. R. (2002). Word Studies in the New Testament (Ga 6:1). Bellingham, WA: Logos Research Systems, Inc.
If a man be overtaken (ἐαν και προλημφθῃ ἀνθρωπος [ean kai prolēmphthēi anthrōpos]). Condition of third class, first aorist passive subjunctive of προλαμβανω [prolambanō], old verb to take beforehand, to surprise, to detect. Trespass (παραπτωματι [paraptōmati]). Literally, a falling aside, a slip or lapse in the papyri rather than a wilful sin.
Robertson, A. (1997). Word Pictures in the New Testament (Ga 6:1). Oak Harbor: Logos Research Systems.
The legalist is not interested in bearing burdens. Instead, he adds to the burdens of others (Acts 15:10). This was one of the sins of the Pharisees in Jesus’ day: “For they bind heavy burdens and grievous to be borne, and lay them on men’s shoulders; but they themselves will not move them with one of their fingers” (Matt. 23:4). The legalist is always harder on other people than he is on himself, but the Spirit-led Christian demands more of himself than he does of others that he might be able to help others.
Paul presents a hypothetical case of a believer who is suddenly tripped up and falls into sin. The word overtaken carries the idea of being surprised, so it is not a case of deliberate disobedience. Why does Paul use this illustration? Because nothing reveals the wickedness of legalism better than the way the legalists treat those who have sinned. Call to mind the Pharisees who dragged a woman taken in adultery before Jesus (John 8).
Wiersbe, W. W. (1996). The Bible Exposition Commentary (Ga 6:1). Wheaton, Ill.: Victor Books.
Hughes & Laney
The conflicts over law had led to “conceit” and “jealousy” (5:26). The law did not inspire gentleness and the bearing of each other’s burdens (6:1–2). Paul had to instruct them how to restore the power of the Spirit in their lives. The legalistic perspectives of the false teachers had no room for gentleness or restoration (4:17). They compared themselves to others (6:4; cf. 6:13) and were hindered by pride (6:3). This is the outcome of legalism—false pride and lack of compassion.
Paul dealt with the subject of church discipline (cf. Matt. 18:15–18). When a believer falls into sin, those who are spiritually mature should deal with the matter in a spirit of gentleness. The words “overcome by some sin” (6:1) could mean (1) overtaken and surprised by the transgression, (2) surprised in the transgression, that is, caught “redhanded”, or (3) simply caught up in sin, with no reference to being seen or caught by others. While every Christian should bear his own part of the common load (6:5), believers should assist those excessively burdened.
Hughes, R. B., & Laney, J. C. (2001). Tyndale Concise Bible Commentary. The Tyndale reference library (585). Wheaton, Ill.: Tyndale House Publishers.