Well...so what? For some people their "so what?" is to live a life full of selfish pursuits enabled by the knowledge that their eternal destiny is secure - they have their "eternal life insurance." Not only does a selfish lifestyle beg the question of genuine faith, but at best it deletes the final verse of the chapter. The final verse is Paul's "so what?" indicated by the word, "therefore."
The early church lived in a time when persecution against Christians was on the rise and it would be understandable if they concluded that life was simply to be endured and that all that mattered was their future in heaven. However, Paul says in 1 Cor 15:58, that Christ rose from the dead and our expected response is "work," because so many people need to know him and need to feel his love and need to begin following Him.
Therefore, my beloved brethren, be steadfast, immovable, always abounding in the work of the Lord, knowing that your toil is not in vain in the Lord.
New American Standard Bible : 1995 update. 1995 . The Lockman Foundation: LaHabra, CA