James 4:13-15 (WT)
Come now, you who say, “Today or tomorrow we shall go to this city here and spend one year there, where we shall trade and make a profit.” You do not know what will happen tomorrow. What is your life? You are, in fact, a vapor that appears for a short time and then disappears. Instead, you ought to say, “If the Lord wills, we shall live [in this city] and do this or that.”
We don’t know what will happen tomorrow. There’s no guarantee that we’ll even still be alive tomorrow. So let’s embrace the day that we have today. Let’s give today all we’ve got.
I Corinthians 9:24 (WT)
Do you not know that all of those who run in a race certainly do run, but only one receives the prize? Run in such a manner that you may win.
God’s Word sometimes refers to what we do in this life as running a race (See, for example, Hebrews 12:1). I Corinthians 9:24 tells us to “Run in such a manner that you may win.” That would involve us doing our best, not just giving a half-hearted attempt. The Apostle Paul was a great example of this, as seen by what he wrote in I Corinthians 15.
I Corinthians 15:9-10 (WT)
Surely I am the least of the apostles. I am not qualified to be called an apostle because I persecuted the Church of God. However, by the grace of God I am what I am, and His grace toward me has not become vain, but I labored more abundantly than all of them. Yet not I, but the grace of God that was with me.
Paul labored more abundantly than all of them.