I am afraid of you, lest I have bestowed upon you labour in vain.

Yet have I sent the brethren, lest our boasting of you should be in vain in this behalf; that, as I said, ye may be ready: / Lest haply if they of Macedonia come with me, and find you unprepared, we (that we say not, ye) should be ashamed in this same confident boasting.

And ye, in any wise keep yourselves from the accursed thing, lest ye make yourselves accursed, when ye take of the accursed thing, and make the camp of Israel a curse, and trouble it.

Use not vain repetitions

And when he came to the tower, he took them from their hand, and bestowed them in the house: and he let the men go, and they departed.

For yourselves, brethren, know our entrance in unto you, that it was not in vain: / But even after that we had suffered before, and were shamefully entreated, as ye know, at Philippi, we were bold in our God to speak unto you the gospel of God with much contention.