Paul's passionate Letter to the Galatians has occasioned various perspectives (old, new, radical new, apocalyptic, etc.) for explaining Paul's defense of the "truth of the gospel" in it. This book makes an audacious claim that the allegorical passage of 4:21-5:1 is the best vantage point for configuring Paul's theological vision and logic in the letter. Offering a fresh approach for understanding Paul's allegorical practice, it demonstrates how both the Abraham narrative and the book of Isaiah function as a formative matrix for Paul's theology. With an in-depth analysis of these scriptural texts, Paul's two identifications for believers in Christ--belonging to the "Jerusalem above" and being "children of promise" in the pattern of Isaac--receive new clarity and precision. The investigative journey in this book discusses key concepts and texts from Galatians, and addresses questions concerning the shape of Paul's retelling of Israel's story in relation to Jews and Gentiles. The result is a well-grounded interpretation of Paul's conception of the gospel that made him new and continues to bring about new creation in our world.