[Therefore,] my beloved brothers, be steadfast, immovable, always abounding in the work of the Lord, knowing that in the Lord your labor is not in vain. —1 Corinthians 15:58
The word therefore that starts this verse you’ve set your heart to memorize—that word, every time you see it, should raise the question: “What’s it there for?” That word points to the summation of a logical argument, the gathering of thoughts to a conclusion, the crystallization of what has come before it into a diamond of truth to adorn the soul.
Paul writes, "Therefore, my beloved brothers, be steadfast, immovable, always abounding in the work of the Lord, knowing your labor is not in vain." There is in these words affection, admonition, and affirmation, and all of it is undergirded by what precedes the “therefore.”
So what comes before? What nourishes Paul’s affection for his readers such that he would call them “beloved brothers?” What drives Paul’s confidence to set before them such admonitions to unshakeable, determined service? What girds Paul’s heart with such clarity that he can affirm with such faith that their works of service in and to the Lord will not be empty, pointless, or without result?
Go back and read all of 1 Corinthians 15. Stop and do it now. It will only take a few minutes (more if you take your time and savor what Paul has in his heart and so eloquently offers you).
What is the basis for Paul’s affection, admonitions, and affirmations of verse 58? There are five graces in the chapter you've just read:
The life-changing, hope-producing, witnessed and valid gospel of Jesus Christ
The certain, incontestable, post-death resurrection of those who put their faith in Jesus
The awe-inspiring, promise-fulfilling glorification of the mortal bodies of those who put their faith in Jesus, and
The triumph-shouting, sin-stomping, death-defying victory over death and sin of those who put their trust in Jesus
“Therefore!” Because Jesus truly came to save through His death on the cross on our behalf, and because our faith is in Him, we will see a future resurrection even if our bodies die. These bodies that we cherish so much will be raised and perfected just as His was, and death, the worst enemy of all, will not prevail, therefore...therefore—on account of all this—be steadfast, immoveable, always abounding in the work of the Lord, knowing your labor is not in vain.
Therefore beckons us to look at what God has done for us, in the past, in Christ; to consider what He is doing in us in the present in Christ; to marvel at what He will do for us in the future through Christ; and to press on full of faith, full of hope, full of joy, relying on Christ who lives, who triumphed over death, who cannot fail.