The forms of the verbs used in this verse (the temper had tempted you…our labor would be in vain
) are significant. The first verb is in the indicative mood, indicating a measure of certainty with regard to Satan’s temptations, but the second is in the subjunctive mood, indicating that Paul was uncertain whether the Thessalonians had turned away from Christ.1,2 Though Paul by no means expected the Thessalonians to fall away from the faith, he nevertheless seems to suggest that it may have been a possibility. This seems to create some tension with the confidence expressed in 1 Thessalonians 1:4–5; 1 Thessalonians 2:12; and 1 Thessalonians 5:9, 1 Thessalonians 5:23 regarding the believers’ election, calling, and perseverance, a tension which can be found more widely in the New Testament between warning passages like Hebrews 2:1–3; Hebrews 3:12; Hebrews 4:1, etc. and passages of assurance like John 10:28–29; Romans 8:28–39; Philippians 1:6, etc.3,4
For centuries, Christians and theologians have been exercised by the tension between the so-called warning passages and passages which assure believers of their election and final salvation. It is obviously not possible to do justice to the issue here, but it may help to make the following two comments. Firstly, it is possible for a person to profess faith in Christ without being truly born-again. God’s assurances to believers are not compromised in any way if such a person turns away from his profession, since he was not truly a believer in the first place (cf. John 6:60–66). Secondly, Paul’s urgent desire to see the Thessalonian believers and encourage them in their faith does not stand at odds with his confidence that God had chosen them and would preserve them. One should rather understand Paul’s (and Timothy’s) pastoral care as one of the means which God used to preserve them in their faith. In other words, God works through means; the fact that means are used (in this case, Paul’s concern and encouragement) does not mean that God is not at work.5
5 For this reason, when I could bear it no longer, I sent to learn about your faith, for fear that somehow the tempter had tempted you and our labor would be in vain.