Mathematicians (please do not let that word keep you from continuing to read) talk about relationships that are inversely proportionate to one another. A simple equation such as y=1/x is an example of an inverse relationship. As x gets larger, y gets smaller. For instance, if x = 10 then y is 1/10 or 0.1, but if x = 100 then y is 1/100 or 0.01. Inverse relationships are upside down ones.
Sin behaves this way upon the soul. Simply stated, the more self-centered we are, the less we reflect true humanity.
Examples abound of the inverse relationship of sin and soul. Studies show that the more that money becomes the center of one's life, the less generous that person is. As a _New York Times _article put it:
For decades, surveys have shown that upper-income Americans don’t give away as much of their money as they might and are particularly undistinguished as givers when compared with the poor, who are strikingly generous. A number of other studies have shown that lower-income Americans give proportionally more of their incomes to charity than do upper-income Americans.
This should not overly surprise us. After all, Jesus Himself pointed out that the widow's offering of two mites weighed more on the kingdom's scales than the money bags of the rich. Yet being poor is no sure escape from this rule, for was not this impoverished but wise widow the exception rather than the rule? Ministry with the poor has shown us that there is an inverse relationship between the poor and pets - the less money they have, the more pets you can expect to find in their homes. And cigarette butts and lottery ticket stubs.
Politicians demonstrate this law of inverse proportionality all the time though, like cheating math students, they manipulate the facts a bit, relabel terms, then write down the answer they know is in the key. For example, they increase revenue (i.e. raise taxes) and investments (i.e. spending) to stimulate (i.e. manipulate) some sector of the economy, which seems to be a direct relationship. Yet closer examination shows that these practices bring inflation and staggering debt, which makes us less prosperous in the long-term, not more. And when it comes to helping the poor, it seems the politicians could not get things more upside down. Politicians point to the poor to get at your heart so you will care for their policies. Notice how the Scriptures point to your heart to get to the poor so you will care for your neighbor.
The more and more life revolves around one's own soul, the less and less human one becomes. Like a black hole, the force is so great the light is unable to escape anymore. As Hitler's ego grew, the Jewish population declined. As one young man retreated further into self-righteous anger and video games, he was not able to have compassion even for little schoolchildren. As married men delight secretly in pornography, the wife they once loved is treated more like a machine with a purpose than a woman with a heart. As sure as a math formula, as the x of selfishness increases, the y of soul diminishes and approaches the eternity of death.
Yet thankfully this formula holds in both directions. For is that not what Christ has shown us? When Christ "made himself nothing" by becoming man and going to the cross, then God "highly exalted him and bestowed on him the name that is above every name" (Philippians 2:7, 9). His zero self-centeredness gave Him eternal glory and us eternal life. You learn as you trust and follow Him that the less you care for self, the more human and God-reflecting you become and, amazingly, there is more of you to give. As C. S. Lewis has Screwtape say in one of his letters:
“When He [God] talks of their losing their selves, He means only abandoning the clamour of self-will; once they have done that, He really gives them back all their personality, and boasts (I am afraid, sincerely) that when they are wholly His they will be more themselves than ever.”
That's the true formula of gospel living. Perhaps John the Baptist stated it most simply yet elegantly, "I must decrease, but He must increase" (John 3:30).