The following is adapted from What Is a Healthy Church Member? by Thabiti Anyabwile (Crossway).
"Ignorance of God—ignorance both of His ways and of the practice of communion with Him—lies at the root of the church's weakness today." That's how J. I. Packer began the 1973 preface to his classic volume Knowing God. Packer reasoned that one trend producing such ignorance of God and weakness in the church was "that Christian minds have been conformed to the modern spirit: the spirit, that is, that spawns great thoughts of man and leaves room for only small thoughts of God."
Sadly, Packer's observation rings true more than three decades later. Ignorance of the ways of God and of communion with him is rampant in too many instances. Members of Christian churches continue to think small thoughts of God and great thoughts of man. This state of affairs reveals that too many Christians have neglected their first great calling: to know their God. Every Christian is meant to be a theologian in the best and most intimate sense of the word. If churches are to prosper in health, church members must be committed to being biblical theologians in whatever capacity they can. This is the second mark of a healthy church member.
What Is Biblical Theology for the Church Member?
To practice biblical theology is to know God himself. I'm using the term "biblical theology" with two things in mind. First, we must keep in mind that the Bible is the self-revelation of God; it is the source material for developing great thoughts about God. The Christian who is interested in knowing his God is the Christian who wants to know what God says about himself in the Bible. Such a Christian will not begin sentences with "I like to think of God as . . ." She has learned not to blend together a little New Age or a little Hinduism with a little Christianity in order to yield a custom-fitted deity for herself. No, the Christian church member who is serious about knowing God is the member who is committed to what the Bible says about God, because the Bible is where God tells us about himself.
To practice biblical theology is to know God's macro story of redemption. Second, the biblical theologian is a person committed to understanding the history of revelation, the grand themes and doctrines of the Bible, and how they fit together. In other words, healthy church members give themselves to understanding the unity and progression of the Bible as a whole—not just isolated or favorite passages. They approach the Bible knowing that they are reading one awesome story of God redeeming for himself a people for his own glory. And in that story, they see that God is a creating God, a holy God, a faithful God, a loving God, and a sovereign God as he makes and keeps his promises to his people, beginning with Adam and Eve and progressing to the final consummation of all things.
How Does Biblical Theology Work to Promote Health in a Church Member?
In his popular Systematic Theology, Wayne Grudem outlines several benefits to studying systematics. Many of those benefits come with doing biblical theology as well. Grudem's proposed benefits are worth summarizing here.
First, practicing biblical theology helps us grow in our reverence for God. As we encounter the God of Scripture who establishes and keeps his covenant promises with his people, we see something of God's majesty. The Lord's working of all things together for good comes into clearer focus, from his promise to the woman that her Seed would bruise the serpent's head (Gen. 3:15), to the opening of barren wombs so that the Seed would be preserved (Gen. 17:15–19; 21:1–2; 29:31; 30:22; Isa. 7:14), to the actual birth of that Seed (Matt. 1:20–23). When we see that God is, always has been, and always will be the same creating, holy, faithful, loving, and sovereign God for us that he has been for others, we are stirred to faith and awe in God. If we want to know and reverence God truly, we will dedicate ourselves to becoming biblical theologians who understand the narrative and themes of Scripture.
Second, practicing biblical theology helps us to overcome our wrong ideas. All of us encounter various teachings in the Bible that challenge, confuse, or provoke us. Often, we refuse to accept these teachings because of dullness and sin in our hearts. We can evade one verse here or there that displeases or confronts us. But when we give ourselves to understanding the grand sweep of biblical revelation and the total weight of Scripture's teaching on a particular subject, we are more readily convinced of our wrong ideas. Biblical theology helps us to see how God has consistently spoken the same message to his people in diverse places and diverse ways (Heb. 1:1), a message that we will all one day bow to and accept (Isa. 45:22–24; Rom. 14:10–12; Phil. 2:9–11). As we prayerfully study biblical theology, we're led to joyfully submit to God and to jettison our wrong ideas about him.
Third, practicing biblical theology helps inoculate the church against doctrinal controversies. Church history is replete with controversies rising within and between congregations. Churches are better able to withstand and productively resolve such controversies when they maintain a good understanding of biblical, systematic, and historical theology. This is true because whatever the Bible has to say about one thing is related to everything else the Bible says. Biblical theology helps to maintain the continuity and consistency of the Bible's teaching. Engaging in biblical theology is akin to putting together a jigsaw puzzle. When one piece of the puzzle appears unfamiliar, we can search for its proper place in the puzzle by relating it to the bigger picture on the puzzle box. The more pieces we have in place to begin with, the easier it is to evaluate and fit in new pieces and the less apt we are to make mistakes. Adequately grasping biblical theology is much like having the picture of the completed puzzle, allowing us to accept or reject errant theological pieces. The Scriptures "were written down as warnings for us, on whom the fulfillment of the ages has come" (1 Cor. 10:11), and knowledge of Scripture protects the church from clever wives' tales and endless disputes.
Fourth, the practice of biblical theology is necessary to fulfilling the Great Commission. Jesus commands us to teach all believers to observe all that he commands (Matt. 28:19–20). Without a well-formed theology, including an accurate understanding of how God's commands are to be understood in their historical development and context, it is difficult indeed to obey the Lord's command to teach others to obey. What shall we teach? What shall we obey? How shall we know what to apply to our lives? These questions are better answered when Christians are knowledgeable of biblical theology and know their God.
But perhaps the most compelling benefit for doing biblical theology is that it deepens our understanding of and facility with the gospel. Jesus and the apostles did not need the New Testament to proclaim the gospel. They relied on the Old Testament and understood that the Old Testament Scriptures pointed to Jesus (Luke 24:27, 44–45). The biblical theologian follows in the steps of Jesus and the apostles by mastering the unity of Scripture, seeing Christ and the gospel throughout.
In the next article in this series, I will explain how you as a church member can become a biblical theologian.
 J. I. Packer, Knowing God, 20th Anniversary Edition (Downers Grove, IL: InterVarsity, 1993), 12.
 Mark Dever, Nine Marks of a Healthy Church (Wheaton, IL: Crossway Books, 2004). See chap. 2.
 Wayne Grudem, Systematic Theology (Grand Rapids, MI: Zondervan, 1994), 26–30.
Adapted from What Is a Healthy Church Member? by Thabiti Anyabwile (Crossway).