Galatians 2:2
2 I went up because of a revelation and set before them (though privately before those lwho seemed influential) the gospel that mI proclaim among the Gentiles, nin order to make sure I was not running or had not orun in vain.
1 Thessalonians 3:5
5 For this reason, iwhen I could bear it no longer, iI sent to learn about your faith, jfor fear that somehow kthe tempter had tempted you and lour labor would be in vain.
Galatians 4:11
11 I am afraid sI may have labored over you in vain.