The doctrine of justification stands at the center of our reflection on the meaning of salvation, mission, and life together. In volume 1, Michael Horton explores justification from the patristic era to the Reformation under the broader rubric of the “great exchange.” In doing this he provides a map for contemporary discussions of justification, identifying and engaging his interlocutors from Origen to the magisterial Reformers. His first study concludes by examining the hermeneutical and theological significance of the Reformers’ understanding of the law and the gospel and the resultant covenantal scheme that became formative in Reformed theology, opening the door to the constructive task of volume 2—to investigate the biblical doctrine of justification in light of contemporary exegesis.