“Therefore, my beloved brethren, be ye stedfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labour is not in vain in the Lord.”
King James Version (KJV)
15:58 Be ye steadfast - In yourselves. Unmovable - By others; continually increasing in the work of faith and labour of love. Knowing your labour is not in vain in the Lord - Whatever ye do for his sake shall have its full reward in that day. Let us also endeavour, by cultivating holiness in all its branches, to maintain this hope in its full energy; longing for that glorious day, when, in the utmost extent of the expression, death shall be swallowed up for ever, and millions of voices, after the long silence of the grave, shall burst out at once into that triumphant song, O death, where is thy sting? O hades, where is thy victory?
1Co 15:58 Therefore, brethren, be ye steadfast, unmoveable. Firm as a rock, devoted to Christian life, for their "faith is not vain". Compare 1Co 15:14,17. Ye know that your labour is not vain in the Lord. Jesus Christ is The Resurrection and the Life (Joh 11:25). The hope of immortality hath sure foundations.