The quote is from 1 corinthians 15. verse 31. there is a greater context to it that should be understood.
"I protest by your rejoicing which I have in Christ Jesus our Lord, I die daily. 32 If after the manner of men I have fought with beasts at Ephesus, what advantageth it me, if the dead rise not? let us eat and drink; for to morrow we die. 33 Be not deceived: evil communications corrupt good manners. 34 Awake to righteousness, and sin not; for some have not the knowledge of God: I speak this to your shame."
"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."