“You are the salt of the earth” (Mt. 5:13).
That statement (“you are the salt of the earth”) not only tells us something about Jesus’ disciples it also tells us something about the world; it implies that the world is rotting. It’s similar to Jesus’ next statement, “You are the light of the world” (Mt. 5:14a), which again, tells us something about His people, as well the world they live in; namely, that the world is in darkness. So if you’ve ever watched the news and thought something like, “This world is going crazy,” not as a manifestation of a ‘holier-than-thou’ mentality but as a kind of ‘knee-jerk reaction’ to either the reported or celebrated sin of men and women, you’d be closer to a biblical worldview that you might have at first realized. The natural bent of the unbelieving world is not towards godliness but ungodliness, as evidenced by, say, the fact that a universal flood to judge universal wickedness followed the fall as opposed to man-made, God-glorifying utopia. Nonetheless, one of the reasons why the corrosion has not gone farther and one of the reasons why it has not become even darker is because God has scattered His people like salt across a corroding earth and He has sent His people like light into darkness. The Christian’s presence is like a preservative to society.
It’s worth remembering that salt cannot bring about molecular regeneration or recreation, it simply slows the decaying process. So while there are limitations to what salt can do, those limitations do not diminish the positive benefits of it, one of which is – it is a preservative. And in like manner, so are Christians in the earth. Here’s an example of a man whose life, ministry, and public service had an incredible salt-like effect upon society.
William Wilberforce (1759-1833) was a mighty, and perhaps the primary, instrument in the hands of God’s providence to bring about the abolition of the slave trade in the British colonies. William began serving in the English Parliament when he was twenty-one years old and he served for over fifty years in English politics until he died a day before his seventy-fourth birthday. Although he began such public service in 1780 he didn’t come to saving faith in Jesus Christ until 1785. Two years later on October 28th, 1787 he wrote in his diary:
“God Almighty has set before me two great objects, the suppression of the Slave Trade and the Reformation of Manners [i.e. morals].”
To be clear, Wilberforce was far from simply a religious moralist. His writings make clear that he loved God, the Gospel, God’s Word, and Christian doctrine. It was in light of those loves that he committed the rest of his life and public service to the cessation and abolition of the slave trade in Great Britain. It was not an easy road; nor was it a short road. In fact, it wasn’t until three days before he died on July 26th, 1833, forty-six years after the previously quoted diary entry, that the vote finally came and slavery was officially outlawed in the British colonies.
Think of how this applies to you. Granted, the history books may not record your Bible-driven, heroic pursuit of some reform or another, but that doesn’t mean that you are not a God-ordained preservative wherever you are. Perhaps at your place of work, when you walk into the room, people stop talking about obscene things because they know you’re Christian. Perhaps you work with someone who wants to divorce their spouse and you have encouraged them to pursue loving their family rather than getting divorced because they had no Biblical grounds to pursue doing so. Perhaps you routinely pray for your country and while you cannot quantify the effectual nature of such prayers you trust that in some way, shape, or form, God has used such intercession as a means by which He has advanced His kingdom and slowed the decay of the kingdoms of this world. Perhaps you are a parent training up your child in the nurture and admonition of the Lord and that child, by God’s grace, will serve his or her church and the community in which they live in Jesus’ name. Whatever the case might be, whatever the specifics are, if you are a repentant, Christ-following, Gospel-believing Christian, you are identified as the light of the Lord to a dark world (Eph. 5:8b) and you are, at the same time, commanded to live as light (vs.8c). In light our current consideration, and particularly Matthew 5:13, you could say – ‘You are the salt of the earth; live as salt.’
Therefore, may you be exhorted today to freshly embrace your part in the unpublicized pages of Christian history, joining multitudes of saints that have tangibly lived out their calling as salt that doesn’t lose its saltiness.
 William Wilberforce, A Practical View of Christianity, p. 90 (quoted in John Piper’s, The Roots of Endurance: Invincible Perseverance in the lives of John Newton, Charles Simeon, and William Wilberforce, p. 119.)