23 Free Theology Books [PDF]
by InfoBooks
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.
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PDF • 4183 pages • 8.74 MB#1 Summa Theologica
Author: Saint Thomas Aquinas
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.
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PDF • 1277 pages • 6.88 MB#2 The Institutes of the Christian Religion
Author: John Calvin
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).
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#3 The Institutes of the Christian Religion
Author: John Calvin
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).
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PDF • 833 pages • 3.35 MB#4 Systematic Theology
Author: Louis Berkhof
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.
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PDF • 646 pages • 3.26 MB#5 Systematic Theology, Volume I
Author: Charles Hodge
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.
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PDF • 872 pages • 2.35 MB#6 Systematic Theology, Volume I
Author: Augustus Hopkins Strong
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.
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PDF • 397 pages • 1.8 MB#7 Abstract of Systematic Theology
Author: James Petigru Boyce
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.
Biblical Theology Books
Biblical theology traces God's revelation through Scripture, from Genesis to Revelation. A different approach from systematics, focused on the Bible's own structure.
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PDF • 493 pages • 1.77 MB#1 Biblical Theology
Author: Geerhardus Vos
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.
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PDF • 230 pages • 0.76 MB#2 Biblical theology
Author: Harvestime
A comprehensive survey of ten major theological disciplines: Paterology, Christology, Pneumatology, Angelology, Demonology, Bibliology, Harmartiology, Soteriology, Ecclesiology, and Eschatology. Includes self-tests per chapter.
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PDF • 45 pages • 0.67 MB#4 Biblical Theology
Author: Graeme Goldsworthy
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.
Christian Theology Books
These books explore Christian theology from different traditions and eras. Topics range from church history to the foundations of Christian thought.
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PDF • 54 pages • 0.26 MB#1 Christian Theology
Author: Judith Wolfe
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.
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PDF • 120 pages • 0.38 MB#2 Introduction to Theology
Author: Alpha Institute
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.
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PDF • 54 pages • 0.48 MB#3 Glorious Institution: The Church in History
Author: Stanford Murrell
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.
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PDF • 171 pages • 1.19 MB#4 A Glorious Institution: The church in history, Parts Three and Four
Author: Stanford Murrell
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.
Soteriology Books
Soteriology is the study of salvation. These books cover key doctrines like justification, sanctification, and glorification.
If you want to understand what the Bible teaches about how people are saved, start here.
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PDF • 188 pages • 4.98 MB#1 Soteriology: The Doctrine of Salvation
Author: Bible.org
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.
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PDF • 88 pages • 0.55 MB#2 Soteriology: The Doctrine of Salvation
Author: Rick Estell
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.
Theology Guides
Short guides and reference materials for anyone starting in theology. Useful for seminary students and self-directed learners alike.
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PDF • 33 pages • 0.11 MB#2 Theological Anthropology
Author: Faith and Unity Commissioners of the National Council of Churches in Australia
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.
That wraps up our collection of free theology books in PDF.
Other Religion Books
Angel Books
Celestial beings, protection, faith. Exploring the role of angels across traditions.
Children's Religion Books
Faith, values, stories. Introducing religious concepts to young readers.
Demonology Books
Demons, evil, exorcism. The study of malevolent supernatural entities.
Catechism Books
Doctrine, instruction, faith. Systematic teaching of religious principles.
Christian Books
Jesus, gospel, faith. Books about Christianity and Christian living.
Adventist Books
Sabbath, prophecy, health. The beliefs and teachings of the Adventist church.
Atheism Books
Nonbelief, reason, secularism. Arguments and perspectives against the existence of God.
Freemasonry Books
Brotherhood, symbols, tradition. The teachings and history of Freemasonry.
Homiletics Books
Preaching, sermons, rhetoric. The art and practice of delivering sermons.
Sacred Books
Holy texts, wisdom, devotion. Sacred writings from the world's spiritual traditions.
Santeria Books
Orishas, rituals, Afro-Caribbean. The syncretic religion of Santeria.
Agnosticism Books
Uncertainty, inquiry, questioning. The position that ultimate truth about God is unknowable.
Christian Books for Young Adults
Faith, youth, guidance. Christian resources for young adult readers.
Prayer Books
Devotion, worship, meditation. Collections of prayers from various traditions.
Spirituality Books
Soul, transcendence, inner life. Exploring the spiritual dimension of human experience.
Apocryphal Books
Hidden texts, non-canonical, ancient. Biblical books not included in the standard canon.
The Bible
Scripture, Old and New Testament, faith. The foundational text of Christianity.
New Testament Books
Gospels, epistles, Jesus. The second part of the Christian Bible.
Old Testament Books
Genesis, prophets, law. The first part of the Bible, shared with Judaism.