Systematic theology seeks to understand and render more intelligible the central doctrines of faith and to show how they are related to each other. It tries to demonstrate how these doctrines are rooted in Scripture and develop in the history of the church; most important, it strives to more adequately express and sometimes reinterpret the church’s doctrinal tradition, always in the interest of better communicating the mystery of salvation and bringing it into a dialogue with culture. The present text is intended to be concise and accessible, an introduction that explores basic themes in Catholic systematic theology from a biblical, historical, and contemporary perspective, always aware of today’s theological pluralism.