If you think about God, you are already doing theology. Grenz and Olson introduce theology as something every Christian practices, not a subject reserved only for specialists. They explain what theology is, why it matters to the church, how Scripture functions in theological reflection, and why ordinary believers should learn to think carefully about faith.
That does not diminish the extraordinary contribution of scholars and teachers such as R.C. Sproul, Charles Spurgeon, and so many others who have helped the Church think deeply and faithfully about God. Their work deserves our respect and careful attention.
But theology is not only for scholars. Every believer is called to think carefully about who God is, what He has done, and what that means for how we live. The real question is not whether we are theologians, but whether we are becoming thoughtful and faithful ones.