Do not labor for the food that perishes, but for the food that endures to eternal life, which the Son of Man will give to you. – John 6:27"We should mark ... in this passage, what Christ advises. He tells us to "labor for the food that endures to everlasting life." He would have us take pains to find food and satisfaction for our souls. That food is provided in rich abundance in Him. But he that would have it must diligently seek it.
How are we to Labor? There is but one answer. We must labor in the use of all appointed means. We must read our Bibles, like men digging for hidden treasure. We must wrestle earnestly in prayer, like men contending with a deadly enemy for life. We must take our whole heart to the house of God, and worship and hear like those who listen to the reading of a benefactor's will. We must fight daily against sin, the world, and the devil., like those who fight for liberty, and must conquer, or be slaves. these are the ways we must walk in if we would find Christ, and be found in Him. This is "laboring." This is the secret of getting on about our souls.
Labor like this no doubt is very uncommon. In carrying it on we shall have little encouragement from man, and shall often be told that we are "extreme," and go too far. Strange and absurd as it is, the natural man is always fancying that we many take too much thought about religion, and refusing to see that we are far more likely to take too much thought about the world. But whatever man may say, the soul will never get spiritual food without labor. We must "strive," we must "run," we must "fight," we must throw our whole heart into our soul's affairs. It is the violent who take the kingdom. (Matt. 11:12)"
—J.C. Ryle, The Gospel of John