"Every Christian is a theologian. We are always engaged in the activity of learning about the things of God. We are not all theologians in the professional sense, academic sense, but theologians we are, for better or worse. The ‘for worse’ is no small matter. Second Peter warns that heresies are destructive to the people of God and are blasphemies committed against God. They are destructive because theology touches every dimension of our lives. The Bible declares that as a man thinks in his heart, so is he…Those ideas that do grasp us in our innermost parts, are the ideas that shape our lives. We are what we think. When our thoughts are corrupted, our lives follow suit. All know that people can recite the creeds flawlessly and make A’s in theology courses while living godless lives. We can affirm a sound theology and live an unsound life. Sound theology is not enough to live a godly life. But it is still a requisite for godly living. How can we do the truth without first understanding what the truth is? No Christian can avoid theology. Every one has a theology. The issue, then, is not, do we want to have a theology? That’s a given. The real issue is, do we have a sound theology? Do we embrace true or false doctrine?"
R.C. Sproul, Essential Truths of the Christian Faith, Wheaton, IL: Tyndale, 1992, p. vii