Isaiah 49:4 But I said, "I have toiled in vain, I have spent My strength for nothing and vanity; Yet surely the justice due to Me is with the LORD, And My reward with My God."

Galatians 2:2 It was because of a revelation that I went up; and I submitted to them the gospel which I preach among the Gentiles, but I did so in private to those who were of reputation, for fear that I might be running, or had run, in vain.

Galatians 4:11 I fear for you, that perhaps I have labored over you in vain.

Philippians 1:6 For I am confident of this very thing, that He who began a good work in you will perfect it until the day of Christ Jesus.

1 Thessalonians 3:5 For this reason, when I could endure it no longer, I also sent to find out about your faith, for fear that the tempter might have tempted you, and our labor would be in vain. (NASB ©1995)