The Christian tradition is the Christian's inheritance.

c. 50–120 AD

The Didache

16 chapters of early Christian teaching on ethics, worship, and church life.

c. 70–132

The Epistle of Barnabas

Pseudo-Barnabas

An early Christian treatise cast as a letter, interpreting the Old Testament allegorically to argue that the covenant belongs to Christians rather than Jews. It includes an early form of the Two Ways teaching also found in the Didache.

c. 95–120

Fragments of Papias

Papias

Surviving fragments from the lost five-volume Exposition of the Oracles of the Lord by the Bishop of Hierapolis, preserved mainly through quotations in Irenaeus and Eusebius. Papias is a key witness to early traditions about the Gospels and apostolic teaching.

c. 96

First Epistle to the Corinthians

Clement of Rome

The earliest surviving letter from the Church of Rome, written to the church in Corinth to address divisions and restore order. Clement appeals to the example of the apostles and the ordering of creation to call the Corinthians back to humility and unity.

c. 2nd–3rd century

Hortatory Address to the Greeks

Justin Martyr (attributed)

An exhortation to the Greeks to abandon paganism, arguing that Moses and the prophets are older and more reliable than Greek poets and philosophers.

c. 2nd–3rd Century

Letter to Diognetus

Unknown Author

12 chapters of early Christian apology on the distinctiveness of the faith.

c. 2nd–3rd century

On the Sole Government of God

Justin Martyr (attributed)

A treatise arguing for monotheism against polytheism, drawing on Greek poets and philosophers who acknowledged a single supreme deity.

c. 2nd–4th Century

The Apostles’ Creed

The ancient baptismal confession of the Christian faith in three articles.

c. 2nd century

The Discourse to the Greeks

Justin Martyr (attributed)

A short address urging Greeks to abandon their mythology and turn to the superior wisdom found in the Hebrew prophets and Christian teaching.

c. 2nd–4th century

The Martyrdom of Ignatius

Anonymous

An account of the arrest, journey, and execution of Ignatius of Antioch in the Colosseum at Rome under Emperor Trajan. Its historical reliability is debated, but it preserves the early church’s memory of one of its most celebrated martyrs.

c. 100–160

The Shepherd of Hermas

Hermas

An early Christian text structured as a series of visions, commandments, and parables delivered to Hermas by angelic figures. Widely read in the early church and sometimes counted among the scriptures, it teaches repentance, moral discipline, and the possibility of forgiveness after baptism.

c. 110–140

Epistle to the Philippians

Polycarp

Polycarp’s letter to the church at Philippi, urging them to persevere in righteousness and warning against the love of money. Written in the shadow of Ignatius’s martyrdom, it is one of the earliest surviving Christian letters outside the New Testament.

c. 110

The Epistles of Ignatius

Ignatius of Antioch

Seven letters written by the Bishop of Antioch while being transported to Rome for execution. Ignatius urges the churches to maintain unity under their bishops, warns against docetism, and expresses his passionate desire for martyrdom.

c. 155–160

Dialogue with Trypho

Justin Martyr

The longest surviving early Christian apologetic work, recording a two-day conversation between Justin and Trypho, a Jewish interlocutor. Justin argues from the Hebrew scriptures that Jesus is the promised Messiah and that the church is the true Israel.

c. 155

The First Apology

Justin Martyr

An open letter addressed to Emperor Antoninus Pius defending Christians against charges of atheism and immorality. Justin explains Christian worship, the Eucharist, and baptism, and argues that Greek philosophy pointed toward the truth fulfilled in Christ.

c. 155–160

The Martyrdom of Polycarp

The Church at Smyrna

The earliest surviving account of a Christian martyrdom outside the New Testament. Written as a letter from the church at Smyrna, it describes the arrest, trial, and death of their aged bishop Polycarp, presenting his suffering as a witness patterned on Christ.

c. 155–161

The Second Apology

Justin Martyr

A shorter defense of Christianity prompted by the unjust execution of Christians in Rome. Justin argues that the Logos (Word/Reason) present in all people finds its fullness in Christ, making Christians the true philosophers.

c. 165–175

Address to the Greeks

Tatian

A fierce polemic against Greek culture and philosophy by a student of Justin Martyr. Tatian argues that Christian wisdom, rooted in Moses, is far older and truer than anything the Greeks produced.

c. 177

A Plea for the Christians

Athenagoras of Athens

An elegant apology addressed to Emperor Marcus Aurelius and his son Commodus, refuting charges of atheism, cannibalism, and incest against Christians. Athenagoras makes a philosophical case for monotheism and the resurrection of the body.

c. 177

On the Resurrection of the Dead

Athenagoras of Athens

The earliest surviving treatise devoted entirely to the doctrine of bodily resurrection. Athenagoras argues philosophically that God both can and will raise the dead, and that resurrection is necessary for the full human person to receive just judgment.

c. 180

Against Heresies

Irenaeus of Lyons

The most important theological work of the second century. Across five books Irenaeus exposes and refutes Gnostic systems, develops the doctrine of apostolic succession, articulates the rule of faith, and presents a theology of recapitulation in which Christ restores what Adam lost.

c. 180–200

Fragments from the Lost Writings of Irenaeus

Irenaeus of Lyons

Surviving fragments from lost works of Irenaeus, preserved through quotations in later authors. They supplement Against Heresies with additional teaching on creation, the soul, and the interpretation of scripture.

c. 180

Theophilus to Autolycus

Theophilus of Antioch

Three books addressed to a pagan friend, defending Christianity and expounding the doctrine of God. Theophilus is the first known writer to use the word ‘Trinity’ (trias) for the Godhead.

c. 195

Exhortation to the Heathen

Clement of Alexandria

The first work in Clement’s trilogy, calling the Greeks away from the mysteries and mythology of paganism toward the true Logos, Jesus Christ. Clement draws deeply on Greek philosophy and literature to argue that Christianity is the fulfillment of the best in Greek thought.

c. 197

Ad Martyras

Tertullian

A letter of encouragement to Christians imprisoned and awaiting martyrdom, urging them to see their prison as a school of discipline and their coming death as a victory.

c. 197–200

An Answer to the Jews

Tertullian

An argument that the Old Testament prophecies have been fulfilled in Christ and that the new covenant has superseded the old. Draws heavily on the same material later expanded in Against Marcion.

c. 197

Apology

Tertullian

Tertullian’s most famous work, a vigorous legal defense of Christianity addressed to the Roman governors of Africa. He exposes the injustice of persecuting Christians without fair trial, refutes charges of secret crimes, and argues that Christian worship and morality far surpass pagan practice.

c. 197–202

The Shows

Tertullian

An argument that Christians must abstain from the public spectacles — gladiatorial games, chariot races, and theatrical performances — because they are rooted in idolatry and inflame the passions.

c. 198–200

On Baptism

Tertullian

The earliest surviving treatise on baptism. Tertullian explains its institution, necessity, proper administration, and effects, while arguing against the Cainite heresy that denied baptism’s validity.

c. 198–212

On Idolatry

Tertullian

A comprehensive treatment of how Christians should navigate a society permeated by pagan religion, covering occupations, festivals, dress, and speech that might entangle believers in idolatrous practice.

c. 198–200

On Prayer

Tertullian

A commentary on the Lord’s Prayer and an exposition of Christian prayer, covering posture, times, and the spirit in which believers should approach God.

c. 198–203

On Repentance

Tertullian

A treatise on the nature of repentance, distinguishing true conversion from mere regret and discussing the church’s practice of public penance for post-baptismal sin.

c. 198

The Instructor

Clement of Alexandria

The second work in Clement’s trilogy. Christ as the divine Pedagogue guides the baptized in daily life, covering topics from diet and dress to sleep and conduct at banquets, always pointing from outward behavior to inward virtue.

c. 200–206

Against Hermogenes

Tertullian

A refutation of Hermogenes, who taught that God created the world from pre-existing matter. Tertullian defends creation ex nihilo as essential to God’s sovereignty and goodness.

c. 200–203

On Patience

Tertullian

A reflection on patience as the supreme Christian virtue, grounded in God’s own patience toward sinful humanity. Tertullian confesses his own struggle with the virtue even as he commends it.

c. 200

The Prescription Against Heretics

Tertullian

A groundbreaking argument that heretics have no right to appeal to scripture because the scriptures belong to the churches that received them from the apostles. Tertullian’s legal metaphor of praescriptio establishes the principle of apostolic tradition as the criterion of orthodoxy.

c. 200–210

The Stromata, or Miscellanies

Clement of Alexandria

The third and most ambitious work in Clement’s trilogy. A wide-ranging exploration of the relationship between faith and philosophy, arguing that the true Gnostic is the mature Christian who unites knowledge and virtue under the guidance of scripture.

c. 200

Who Is the Rich Man That Shall Be Saved?

Clement of Alexandria

A sermon on Mark 10:17–31 arguing that Jesus does not condemn wealth itself but the enslavement of the soul to possessions. Clement counsels a disciplined use of riches for the service of others and closes with the famous story of the apostle John and the young robber.

c. 203

The Passion of Perpetua and Felicitas

Perpetua, Saturus, and an anonymous editor

One of the most remarkable documents of early Christianity. The prison diary of Perpetua, a young noblewoman, and her fellow catechumens awaiting execution in Carthage. Perpetua’s first-person account of her visions and her father’s pleas is among the earliest surviving writings by a Christian woman.

c. 206–212

Against the Valentinians

Tertullian

A satirical exposé of Valentinian Gnosticism, revealing the absurdity of its elaborate mythology of aeons and emanations. Tertullian relies heavily on Irenaeus but adds his own rhetorical flair.

c. 206–212

On the Flesh of Christ

Tertullian

A defense of the true incarnation against docetism and Marcion. Tertullian insists that Christ took real human flesh, born of a virgin, and that the reality of the incarnation is essential to the reality of salvation.

c. 206–212

On the Resurrection of the Flesh

Tertullian

A treatise defending the bodily resurrection against Gnostic spiritualizers. Tertullian argues from creation, incarnation, the sacraments, and scripture that the flesh is essential to God’s purposes and will be raised.

c. 207–212

Against Marcion

Tertullian

Five books refuting the dualist theology of Marcion, who rejected the Old Testament and taught that the God of Israel was an inferior creator. Tertullian defends the unity of the Creator and Redeemer, the goodness of creation, and the authority of the full biblical canon.

c. 210

A Treatise on the Soul

Tertullian

A philosophical and theological treatise on the nature of the soul, arguing against Platonic and Gnostic views. Tertullian teaches that the soul is corporeal, created with the body, and transmitted from parent to child (traducianism).

c. 211–213

Scorpiace

Tertullian

An antidote to the ‘scorpion sting’ of Gnostic teaching that martyrdom is unnecessary. Tertullian defends the duty and glory of confessing Christ unto death.

c. 211

The Chaplet, or De Corona

Tertullian

Prompted by a soldier’s refusal to wear a military laurel wreath, Tertullian argues that Christians must reject customs rooted in pagan worship, even when scripture does not explicitly forbid them.

c. 212

To Scapula

Tertullian

A brief open letter to the proconsul of Africa warning against persecuting Christians, with examples of divine judgment on persecutors and appeals to the loyalty and harmlessness of the Christian community.

c. 213

Against Praxeas

Tertullian

The most important pre-Nicene treatise on the Trinity. Tertullian coins the Latin formula ‘one substance, three persons’ (una substantia, tres personae) while refuting the modalism of Praxeas, who collapsed the distinction between Father and Son.

c. 318 AD

On the Incarnation

Athanasius of Alexandria

Athanasius’ classic defense of the Incarnation — why the eternal Word took flesh to restore fallen humanity and conquer death.

325 / 381 AD

The Nicene Creed

The definitive creed of the universal church on the Trinity and incarnation.

c. 397–400 AD

Confessions

Augustine of Hippo

Augustine’s autobiographical meditation on sin, grace, memory, and time — the first great Western autobiography.

c. 5th–6th Century

The Athanasian Creed

The most thorough ecumenical creed on the Trinity and the Incarnation.

451 AD

The Chalcedonian Definition

The definitive statement on the two natures of Christ in one person.

c. 397–400 AD

Confessions

Augustine of Hippo

Augustine’s autobiographical meditation on sin, grace, memory, and time — the first great Western autobiography.

c. 1418–1427

The Imitation of Christ

Thomas à Kempis

The most widely read devotional work after the Bible — a guide to the interior life of prayer, humility, and union with God.

1891

Rerum Novarum

Pope Leo XIII

The foundational papal encyclical on the rights of workers, the duties of capital, and the role of the Church in social justice.

1615

Syntagma Theologiae Christianae

Amandus Polanus von Polansdorf

The first fully systematic Reformed scholastic theology, organised on the Ramist bifurcating method by Amandus Polanus von Polansdorf (1561–1610), professor at Basel. The Syntagma covers all loci of dogmatics across ten books and was the leading textbook of the early Reformed orthodoxy, drawn upon by virtually every later Reformed scholastic.

1647

Westminster Larger Catechism

196 questions and answers expanding the Westminster doctrine for further study.

1682

The Existence and Attributes of God

Stephen Charnock

A comprehensive Puritan treatise on the divine perfections — 14 discourses exploring God’s existence, eternity, immutability, omnipresence, and other attributes.

1517

The 95 Theses

Martin Luther

95 propositions challenging the sale of indulgences, sparking the Protestant Reformation.

1530

The Augsburg Confession

28 articles of the Lutheran faith presented to Emperor Charles V at the Diet of Augsburg.

1571

Thirty-Nine Articles of Religion

39 articles defining the doctrinal position of the Church of England after the Reformation.

1928

The Book of Common Prayer

The 1928 American Book of Common Prayer, including the Daily Office, Holy Communion, Sacramental Rites, the Psalter, and the Ordinal.

1536 / 1559

Institutes of the Christian Religion

John Calvin

The foundational work of Reformed systematic theology — covering God, Scripture, Christ, salvation, and the Church across four books.

1561

The Belgic Confession

37 articles of faith confessing the core doctrines of the Christian faith.

1563

The Heidelberg Catechism

129 questions and answers for the Christian life, organized into 52 Lord’s Days.

1615

Syntagma Theologiae Christianae

Amandus Polanus von Polansdorf

The first fully systematic Reformed scholastic theology, organised on the Ramist bifurcating method by Amandus Polanus von Polansdorf (1561–1610), professor at Basel. The Syntagma covers all loci of dogmatics across ten books and was the leading textbook of the early Reformed orthodoxy, drawn upon by virtually every later Reformed scholastic.

1647

Westminster Larger Catechism

196 questions and answers expanding the Westminster doctrine for further study.

1647

Westminster Shorter Catechism

107 questions and answers teaching the essentials of Reformed Christian doctrine.

1682

The Existence and Attributes of God

Stephen Charnock

A comprehensive Puritan treatise on the divine perfections — 14 discourses exploring God’s existence, eternity, immutability, omnipresence, and other attributes.

1689

London Baptist Confession

32 chapters of Reformed Baptist doctrine with scripture proofs from the Second London Confession.

1722–1723

Resolutions

Jonathan Edwards

70 personal resolutions for holy living, written between ages 18 and 20.

1689

London Baptist Confession

32 chapters of Reformed Baptist doctrine with scripture proofs from the Second London Confession.

1974

The Lausanne Covenant

15 articles on world evangelization from the 1974 International Congress at Lausanne.