One of the main criticisms of the market economy leveled by people of faith is that the market thrives on competition, incentivizing the voracious and oppositional features of human existence. Walter Rauschenbusch captured this concern in his classic exposition of what he called “the law of tooth and nail” in Christianizing the Social Order (1912). “The moral instinct of men has always condemned competitive selfishness,” he wrote, “just as it has always admired the moral beauty of teamwork.”
The moral cogency of the argument against competition is enhanced in a framework where the goods that are sought after are static. Whether conceived of in terms of market share or the size of a firm, business and political leaders often use language that makes it seem as if economic gain comes at the expense of others. Indeed, this is an economic perspective with a lengthy historical pedigree. As the New Testament scholar Craig Blomberg writes , this is sometimes called a “theory of limited good,” and it was characteristic of the biblical world: “Most people were convinced that there was a finite and fairly fixed amount of wealth in the world, and a comparatively small amount of that to which they would ever have access in their part of the world so that if a member of their society became noticeably richer, they would naturally assume that it was at someone else’s expense.”
This theory of limited good has been known by many names and taken many forms. The Austrian economist Ludwig von Mises called it  “Montaigne’s fallacy,” after the famous early modern French essayist Michel de Montaigne, and according to which, as Mises put it, “human intercourse cannot consist in anything but the spoliation of the weaker by the stronger.” The Spanish Jesuit Juan de Mariana  (1536-1624), who likewise possessed remarkable wit and intellectual courage, also picked up the idea from the ancient philosopher Plato that “one man’s profit is another’s loss.” This, said Mariana, is one of the “fundamental laws of nature,” and meant that “one man’s loss is another man’s gain. There is no way around that fact.”
It would not be until some of the more historically recent insights into the nature of subjective valuation of goods, innovation, and technological progress that the idea of the amount of wealth in the world as a static thing, a “zero-sum game,”  began to be effectively challenged. But as Charles Murray of the American Enterprise Institute reminds us in a recent commentary in the Wall Street Journal , this destructive view of economic life is still with us: “Americans increasingly appear to accept the mind-set that kept the world in poverty for millennia: If you’ve gotten rich, it is because you made someone else poorer.”
But if economic activity is conceived of as at its core consisting of mutually-beneficial exchanges, then “human intercourse,” to use Mises’ description, need not fundamentally manifest in “spoliation of the weaker by the stronger.” And, indeed, if the measures of economic activity are expanded to include realities beyond market share and relative inequalities, we can see that competition, rightly conceived, can be a force for much good in the world. Market economies tend to reward those who serve others well and meet the needs and wants of their customers. If the competition among various market players is cast as competing to surpass one another in providing increasingly excellent goods and services, then it becomes easy to see the virtue of competition. As the economic educator and entrepreneurial leader Manuel Ayau put it , in a market economy “in a very real sense, we all compete to enrich others.”
The comparative orientation at the heart of competition can certainly work itself out in destructive ways. As Thomas Aquinas noted, when we observe good in others that surpasses what we possess ourselves, there are two basic responses. One is to grieve at the good another possess, to envy it, and very often out of a malicious spirit to seek its destruction. This, says, Aquinas, “is always sinful ,” for “to do so is to grieve over what should make us rejoice,” that is, “our neighbor’s good.” But on observing a good which our neighbor has that we do not possess can also spark a different reaction: zeal for virtue and self-improvement. Observing a relative lack in ourselves, we can be moved to address the lack not by tearing others down but by addressing our own flaws and weaknesses. This zeal is praiseworthy especially when the sought-after good is spiritual, but it can also receive moral approbation when temporal goods are sought after judiciously and prudently.
Where the market economy can engender a spirit of competition, Christians must work to assure that the competitive spirit is expressed in, and when necessary transformed into, a zeal for doing good for others. As the Apostle Paul urges in another context, we should seek to excel one another in serving others: “Outdo one another in showing honor” (Romans 12:10 ESV). When competition is construed as seeking ways to love one another better, it becomes a virtue of the market economy that ought to be celebrated rather than scorned.