Charles Spurgeon Commentary 1 Corinthians 15:58

"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." — 1 Corinthians 15:58 (ASV)

Be ye steadfast, unmoveable, always abounding in the work of the Lord, forasmuch as ye know that your labour is not in vain in the Lord.

"You know," because Christ has risen, and because you also will rise, and because there is a reward of grace stored up for you.

The Lord's people may die, but the Lord's church never dies, and the Lord himself, the ever-living One, is always with us, blessed be his holy name!