One of the reasons I wrote Foundations of Economics is to provide answers to similar questions as they relate to economics. I teach a course of the same name that fulfills the social science general education requirement at Grove City College. While many students take the class merely to fulfill a graduation requirement, many also take it to learn something important about economics.
I begin the class by attempting to communicate why it is worth anyone's while to study economics. College classes do not come cheap these days, so it is nice for students to understand they are getting their money's worth.
As I see it there are two primary reasons for the study of economics. In the first place, God manifests His glory by his works in the created order, so economic laws and how people interact constrained by these laws manifest God's glory. Romans 1:19-20 reads
The Bible tells us that God reveals Himself to us not only in Scripture, but also in the created order, what theologians call general revelation. We can learn more of God's eternal power and divine nature by contemplating the economic laws that God has established.
For what can be known about God is plain to them, because God has shown it to them. For his invisible attributes, namely, his eternal power and divine nature, have been clearly perceived, ever since the creation of the world, in the things that have been made. So they are without excuse.
Additionally, the cultural mandate given in Genesis 1 and 2 requires economic development. God tells us to be fruitful and multiply, fill and rule the earth, and to work and keep creation. Doing so requires economic progress that allows us to sustain a growing population while we build things and cultivate the potentialities God has put into the created order. In a sense, consequently, economics is practically helpful in our fulfilling the material aspect of the cultural mandate.
Whether they know it or not, economists, public intellectuals, rulers, and voters who advocate various economic policies are all pushing for various means to achieve the cultural mandate. Economic theory and history both teach us that different economic policies can have very different outcomes. Therefore, we must make wise policy decisions if we do not want to contribute to poverty, death, and the decline of civilization. That begs the question, which economic policies are wise and how do we know?
As I tell my class, just as the stability of the house depends not on the roof, but on its foundation, our analysis of economic policy requires us to make sure our intellectual foundations are secure. Whether we are correct in assessing economic policy ultimately depends on the soundness of our economic theory, which depends on our view of man, which in turn depends on our understanding of ultimate things (i.e. our philosophy and theology). The foundations of our economics, consequently, are very important.
Those interested in how I approach the foundations of economics in class can take a look at the course syllabus. In use my own book as the main required text along with Herbert Schlossberg's Idols for Destruction. I also include supplemental readings from the likes of Ludwig von Mises, Murray Rothbard, Carl Menger, E. Calvin Beisner, Francis Wayland, Adam Smith, Alfred Marshall, Paul Ehrlich, and Karl Marx.