1 Thessalonians 1:3-10 describes the Thessalonians' faith and reception of Paul, demonstrating that his coming was not in vain as stated here.

1 Thessalonians 3:5 expresses Paul's fear that his labor might be in vain, contrasting with the assurance here that it was not in vain.

In 1 Thessalonians 1:5, the gospel came with power and conviction—evidence that the visit was not in vain as claimed here.

In 1 Thessalonians 1:9, the Thessalonians' turn from idols to God demonstrates the effective reception—confirming the claim in 2:1 of a fruitful visit.

Psalm 127:1 teaches that without the Lord all labor is in vain, reinforcing that Paul's fruitful ministry was built on divine blessing.

Isaiah 49:4 has the Servant lament laboring in vain yet trusting God, while Paul declares his own labor actually resulted in success.

Isaiah 65:23 promises God's people will not labor in vain, a blessing Paul sees fulfilled in his own apostolic work among you.

1 Corinthians 15:2 warns that belief can be in vain if not persevered, while Paul's preaching here was not in vain because they believed.

1 Corinthians 15:10 declares that God's grace toward Paul was not in vain, directly mirroring his claim that his labor among you was not in vain.

1 Corinthians 15:58 assures believers their labor in the Lord is not in vain, exactly the same confidence Paul expresses about his own work here.

In Galatians 4:11, Paul fears he labored in vain among the Galatians—contrasting the confident assertion here that the visit was not in vain.

In Acts 20:18, Paul also appeals to their personal knowledge of his conduct—similar use of 'you yourselves know' to validate his ministry.

2 Corinthians 6:1 urges believers not to receive God's grace in vain, a concern that Paul's ministry here was not in vain because it was received.

2 Thessalonians 3:1 asks prayer that the word may spread as it did among the Thessalonians, confirming Paul's visit was effective (not in vain).