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

After camping out for most of chapter 15 in the future talking about the future resurrection of the godly, Paul brings His audience back to the present in verse 58 by calling for them to “stand firm” upon these truths and “work hard” in light of them.    

First he tells his readers to “Stand firm.” He says, “Be steadfast and immovable.”  “Steadfast” is an adjective that means to be sitting.  Paul says “Take your seat on this truth—be fixed, settled, and seated upon it.” 

He says, “What I have told you about your future resurrection is true, therefore stand firm on that truth.”  Paul knows that if this core doctrine of our future resurrection ever waivers, we will begin to live like the world.  If we question the eternal we will lose a kingdom perspective and fail to live with eternity in mind in the present.  For that reason, we must stand firm on these truths and must not let our flesh, the world or the enemy move us from them. 

Second, Paul says, “Work hard" with the truth of your future resurrection in mind.  Now there are two words in the second half of this verse that need attention.  First is the word “work” and second is the word “abounding.” 

The word “work” means to labor to the point of exhaustion or perspiration.  Paul says, “Work until you are wearied.”  His point  here is that there is no vacation time in ones spiritual life.  We are to always be striving—always to be seeking to grow in our knowledge of God from His word and always to be living for His glory. 

The word "abounding" means to overdo it on purpose.  Paul says that we are to be going above and beyond in our spiritual lives—purposefully overdoing it for the Lord.  It should never be said of us that we settled for a sub-par Christian life.