Looking for theology books? We've gathered 23 free theology books in PDF, covering systematic theology, biblical theology, Christian doctrine, soteriology, and practical theology guides.
From Thomas Aquinas' Summa Theologica to John Calvin's Institutes, these are works that shaped how millions understand God, faith, and doctrine. Whether you're a seminary student or simply curious about the deep questions, there is something here for you.
Browse by topic or scroll through our picks. Every book is free to read online or download as PDF.
Systematic Theology Books
Systematic theology covers Christian doctrine in an organized framework. These books address the nature of God, the Trinity, creation, sin, and redemption.
You'll find both classic works and seminary textbooks, from Reformed and Orthodox traditions.
The complete Summa Theologica by Thomas Aquinas covering the nature of God, the Trinity, creation, morality, and the sacraments. One of the most influential works in Western theology and philosophy.
Calvin's magnum opus in four books: Knowledge of God the Creator, Knowledge of the Redeemer, Grace of Christ, and the Holy Catholic Church. Translated by Henry Beveridge (CCEL edition).
A complete systematic theology textbook covering all major doctrines from prolegomena to eschatology. Used in seminaries worldwide for nearly a century, this Reformed classic by Louis Berkhof remains a standard reference.
Volume I of Charles Hodge's three-volume systematic theology covering theological method, the nature and attributes of God, and the Trinity. A foundational work of Princeton Reformed theology from the 19th century.
Volume I of Strong's comprehensive systematic theology covering theology proper, the existence of God, Scripture, and the nature of divine attributes. A major Baptist contribution to systematic theology with philosophical rigor.
A concise systematic theology covering doctrines from God's nature to eschatology. Written by the founder of the Southern Baptist Theological Seminary, this 1887 classic presents Reformed Baptist theology in accessible form.
A seminary-level course on the doctrine of God covering His names, attributes, Trinity, and works. Produced by Christ's Community Study Center in Mbarara, Uganda.
Biblical theology traces God's revelation through Scripture, from Genesis to Revelation. A different approach from systematics, focused on the Bible's own structure.
A landmark work tracing God's revelation through the Old and New Testaments in its historical development. Geerhardus Vos, the father of Reformed biblical theology, examines the Mosaic, prophetic, and apostolic periods.
A comprehensive survey of ten major theological disciplines: Paterology, Christology, Pneumatology, Angelology, Demonology, Bibliology, Harmartiology, Soteriology, Ecclesiology, and Eschatology. Includes self-tests per chapter.
A scholarly study guide on Old Testament theology approaches: thematic, history of redemption, and worldview. Written by Ingrid Faro, Ph.D., with detailed footnotes and bibliography.
Lecture notes on biblical theology exploring the relationship between the Old and New Testaments. Covers hermeneutical principles and the unity of Scripture from a Reformed evangelical perspective.
A comprehensive encyclopedia article on Christian theology from the St Andrews Encyclopaedia of Theology. Covers substance, structure, biblical sources, historical development, and theology as science and art. Licensed CC BY-NC.
A Catholic seminary textbook covering the concept of theology, definitions, branches, history of Christian theology, modern theologians, and contextual theology. Published by Alpha Institute of Theology and Science, Kerala, India.
Parts One and Two of a church history survey covering AD 33-1517. Traces the early church, persecution under Rome, ecumenical councils, the Middle Ages, and the dawn of the Reformation. Published by Chapel Library.
Parts Three and Four covering the Reformation era (1517-1648) and the Modern Age (1648-1900s). Covers Luther, Calvin, Knox, the Counter-Reformation, religious revivals, and challenges to the church in the modern world.
A detailed seminary-level study of the doctrine of salvation covering election, calling, regeneration, faith, justification, sanctification, and glorification. Includes charts, diagrams, and study questions.
A Baptist pastoral study on salvation covering repentance, faith, justification, adoption, and sanctification. Published by Faithway Baptist Church with practical applications for Bible study groups.
A comprehensive overview of soteriology covering ten key topics from the need for salvation to glorification. Organized in clear sections with Scripture references throughout.
Seminary lecture notes on soteriology from Trinity Theological College covering the nature and application of salvation. A clear introduction to the doctrine for theology students.
A collection of ecumenical academic papers on the imago Dei and the human person. Features perspectives from Orthodox, Lutheran, Anglican, Quaker, and Uniting Church traditions.
Faith and Unity Commissioners of the National Council of Churches in Australia
A concise seminary guide on the doctrine of God covering divine attributes, the Trinity, and God's decrees. Lecture notes from Trinity Theological College.
