Doctrine, if we grasp it properly, must make a difference in how we live. Paul affirms this when he says, “Knowledge of the truth . . . accords with godliness” (Titus 1:1). That is, it not only affects the way we think, but it must reorder how we live.

This comes out in each of the Apostle’s letters. He opens up particular truths for his readers and then relates them to the issues they were facing in their churches. God’s truth is always inseparably related to how His people live. Martyn Lloyd-Jones illustrated this in terms of what the skeleton is to the body, or a steel frame to a high-rise building. What people see outwardly in a Christian’s life is shaped and supported by what is unseen and inward.

The study of the great truths revealed in Holy Scripture is never meant to be merely an academic exercise. As J.I. Packer put it, true students of the Bible can never be “balconeers”—people who look into these things in a detached and distant manner.

In that sense, studying the Bible and exploring theology should be unsettling. It is not just that we are studying God’s truth in His Word but also that He Himself is studying and exposing us in the process. Indeed, the more we come to know through the Word, the greater our accountability and responsibility before God. From those to whom much has been given, much will be required (Luke 12:48).

Perhaps nowhere do we feel the weight of this more than in the verse that marks the pivot on which Paul’s letter to the Ephesians turns. The church in Ephesus was one of the most privileged of the New Testament churches. Paul spent two years there during his third missionary journey (Acts 19). Not only had he preached there each Lord’s Day, but he also taught in the hall of Tyrannus every day (v. 9). Ephesus was a veritable precursor to Calvin’s Geneva.

Yet things were going wrong in that church. It was troubled by deep divisions, unresolved disputes, marriage and family issues, and issues of Christian responsibility in the workplace. How, then, does Paul begin to address these problems? With three chapters of some of the most heavy-duty doctrine found anywhere in the Bible—all of which leads to one of its most glorious doxologies (Eph. 3:20–21). Then comes the turn: “I therefore, a prisoner for the Lord, urge you to walk in a manner worthy of the calling to which you have been called” (4:1).

Having immersed his readers in the deep and exalted truths of God in the gospel—all of which converge and crystallize in Christ our Savior—he calls them to live up to and live out the privileges we have in Christ. When we do so, the watching world will see God’s beauty in us and be drawn to ask for its secret. Therein lies the greatest challenge of doing theology.

For Further Study