1 Corinthians 15:2, 58
1 Corinthians 15:2 ASV
by which also ye are saved, if ye hold fast the word which I preached unto you, except ye believed in vain.
1 Corinthians 15:58 ASV
Wherefore, my beloved brethren, be ye stedfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labor is not vain in the Lord.