Book excerpt: Historical Theology presents the key pillars of the contemporary church and the development of those doctrines as they evolved from the history of Christian thought. Most historical theology texts follow Christian beliefs in a strict chronological manner with the classic theological loci scattered throughout various time periods, movements, and controversies—making for good history but confusing theology. This companion to the classic bestseller Systematic Theology is unique among historical theologies. Gregg Allison sets out the history of Christian doctrine according to a topical-chronological arrangement—one theological element at a time instead of committing to a discussion of theological thought according to its historical appearance alone. This method allows you to: Contemplate one tenet of Christianity at a time, along with its formulation in the early church—through the Middle Ages, Reformation, and post-Reformation era, and into the modern period. Become familiar with the primary source material of Christian history's most important contributors, such as Cyprian, Augustine, Aquinas, Luther, Calvin, Barth, and others. Understand the development of evangelical doctrine with a focus on the centrality of the gospel. Discern a sense of urgent need for greater doctrinal understanding in the whole church. Historical Theology is an easy-to-read textbook for any Christian who wants to know how the church has come to believe what it believes today. Gregg Allison's clear and concise structure make this resource an ideal introduction to Christian doctrine.