KJV - 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.
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.
BBE - For this cause, my dear brothers, be strong in purpose and unmoved, ever giving yourselves to the work of the Lord, because you are certain that your work is not without effect in the Lord.
WEB - Therefore, my beloved brothers, be steadfast, immovable, always abounding in the Lord's work, because you know that your labor is not in vain in the Lord.
YLT - so that, my brethren beloved, become ye stedfast, unmovable, abounding in the work of the Lord at all times, knowing that your labour is not vain in the Lord.