The more a religion is aware of its opposition in principle to economic rationalization as such, the more apt are the religion’s virtuosi to reject t… - Max Weber

Luther understands monasticism as a product of an egoistic lovelessness that withdraws from one's duties in the world. By contrast, this-worldly work in a vocation appears to him to be a visible expression of brotherly love, a notion he anchors in a highly unrealistic manner indeed and in contrast—almost grotesquely—to the well-known passages of Adam Smith.

This naive manner of conceptualizing capitalism by reference to a “pursuit of gain” must be relegated to the kindergarten of cultural history methodology and abandoned once and for all. A fully unconstrained compulsion to acquire goods cannot be understood as synonymous with capitalism, and even less as its “spirit.” On the contrary, capitalism can be identical with the taming of this irrational motivation, or at least with its rational tempering. Nonetheless, capitalism is distinguished by the striving for profit, indeed, profit is pursued in a rational, continuous manner in companies and firms, and then pursued again and again, as is profitability. There are no choices. If the entire economy is organized according to the rules of the open market, any company that fails to orient its activities toward the chance of attaining profit is condemned to bankruptcy.
Let us begin by defining terms in a manner more precise than often occurs. For us, a "capitalist" economic act involves first of all an expectation of profit based on the utilization of opportunities for exchange; that is of (formally) peaceful opportunities for acquisition. Formal and actual acquisition through violence follows its own special laws and hence should best be placed, as much as one may recommend doing so, in a different category. Wherever capitalist acquisition is rationally pursued, action is oriented to calculation in terms of capital. What does this mean?

Finally, and of central importance, the special life of the saint—fully separate from the "natural" life of wants and desires—could no longer play itself out in monastic communities set apart from the world. Rather, the devoutly religious must now live saintly lives in the world and amid its mundane affairs. This rationalization of the conduct of life—now in the world yet still oriented to the supernatural—was the effect of ascetic Protestantism’s concept of the calling.