Consider the lilies how they grow: they toil not, they spin not; and yet I say unto you, that Solomon in all his glory was not arrayed like one of these.

If out of free choice one labors intensely without personal benefit, that communicates conviction.

Let nothing move you. Always give yourselves fully to the work ofthe Lord, because you know that your labor in the Lord is not in vain.

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.

Come unto me, all ye that labour and are heavy laden, and I will give you rest.