After the New Testament: Key Apostolic Fathers & Second-Century Texts

By the late first or early second century AD, the last book of the New Testament had been written. In AD 325, the Council of Nicaea would articulate the doctrine of the Trinity and adapt the church’s rule of faith into an official creed. But what happened in between these two watershed moments of church history?

The second century, in particular, was an existentially defining period for the church. The gospel spread far beyond its origins in Galilee, where it was met by serious challenges. The church would emerge from these with greater clarity about its identity and beliefs.

The major voices of this period were the Apostolic Fathers, so-called because they were the first generation of Christian leaders and teachers after the twelve appointed by Christ. Some of them actually knew apostles or knew someone who knew them.

In this article, I will introduce a few writings of the Apostolic Fathers. I have left out a considerable chunk.¹ I have selected those that have special interest for the average New Testament reader. I will organize these works under three major challenges Christians faced in the second century concerning Scripture.

Table of Contents

1. What is the relationship between the Christian faith and the Old Testament?
2. Were the Christians a threat to the Roman state?
3. What are the boundaries of “orthodox” Christianity?
Conclusion

1. What is the relationship between the Christian faith and the Old Testament?

Christianity rose out of the belief that Jesus is the Messiah, the son of Abraham and descendant of David (Matt 1:1). Most (though not all) of the Jewish people had failed to embrace Jesus as the Messiah, and the Jerusalem authorities were culpable for his death. Paul famously laments: “For I could wish that I myself were accursed and cut off from Christ for the sake of my own people, my kindred according to the flesh” (Rom 9:3). At some point, it was becoming clear that non-Jews were listening and responding to the gospel, while most of Paul’s fellow Jews were not (see Acts 28:17–28).

Additionally, within the NT writings themselves, some very difficult things are said about the Jewish people (or leaders): Jesus accuses them of murdering the prophets (Matt 23:30–36), and Matthew reports that the Jewish people have called down divine wrath upon themselves (Matt 27:25).

Articulating the relationship between Christianity and Judaism, and between the Old Testament and the New Testament, was among the earliest problems facing the young church.

The Epistle of Barnabas (c. 70/135)

One of the earliest and most intriguing attempts to provide a response to the question of how Christians should read the Old Testament and understand their relationship to non-Jews is the spurious Epistle of Barnabas—a text of some popularity and significance to Christians in the East.

Barnabas is striking in that it is thoroughly infused with the OT Scriptures, but it takes a strong stance of discontinuity between the new covenant and the practices and rituals of Israel: “Therefore he [God] has abolished these things, in order that the new law of our Lord Jesus Christ, which is free from the yoke of compulsion, might have its offering, not made by man” (Barn. 2:6).² Barnabas even suggests that the physical practice of circumcision was given to Israel through “an evil angel,” and so it has, appropriately, been entirely abolished (Barn. 9:4).

The text is an important witness of the challenge of articulating how Christians should understand their relationship to the historic people of God. Almost certainly, Barnabas is interested in widening the gap between Christians and non-Christian Jews, as he declares his agenda is to prevent his audience from “shipwrecking ourselves by becoming, as it were, ‘proselytes’ to their law” (Barn. 3:6).

Ignatius of Antioch (d. c. 108)

Ignatius was an early second century bishop of Antioch. He is best known for his martyrdom during the reign of Emperor Trajan (AD 98–117). While being escorted to Rome to be executed, a journey which would have taken three to four months, Ignatius managed to pen seven letters: six to churches (Ephesians, Magnesians, Trallians, Philadelphians, Smyrnaeans, Romans) and one personal letter (To Polycarp). These writings are a rich source for understanding the early pastoral and ecclesial theology of the church.

In these letters, one finds strong concerns to encourage the church and exhort them to reject false teachings. For example, Ignatius repeatedly emphasizes the theme of unity. Jesus is united in his humanity and divinity (Eph. 7:2); the faith is united (Eph. 13:1); and Jesus is united with the Father (Magn. 1:2). But Ignatius is also deeply concerned to distinguish Christians from Jews. He emphasizes that the new is superior to the old (Magn. 10:2), and then makes this claim: “It is utterly absurd to profess Jesus Christ and to proclaim Judaism. For Christianity did not believe in Judaism, but Judaism in Christianity in which ‘every tongue’ believed and was ‘brought together’ to God” (Magn. 10:3). Put bluntly, Ignatius warns one church: “If anyone expounds Judaism to you, do not listen to him” (Phld. 6:1).

Marcion (c. 85–160)

Marcion was a wealthy shipowner who gave a substantial gift to the church in Rome and thereby found some level of influence and status as a result. Marcion was the earliest Christian writer (that we know of) to draft a closed list of canonical books, only his canon included no Old Testament, most of Paul’s letters, and a mutilated version of Luke’s Gospel. According to Marcion, there existed the utmost discontinuity between the God of the Old Testament and the God of Jesus Christ. He argued, in fact, that the God of the Old Testament was an angry and vengeful deity, whereas the God of Jesus is loving, forgiving, and gracious.

Marcion wrote one book, Antitheses, which has not survived in its entirety. Judging from attempts to reconstruct this work from bits and pieces quoted in the works of Church Fathers, the work posits contradictory statements between law/OT and gospel/NT in order to show that the God of Israel and the God of Jesus Christ are, in fact, separate deities entirely.

Tertullian of Carthage (c. 155–c. 220)

While many voices rose against Marcion, the strongest anti-Marcion from the second century belonged to Tertullian of Carthage, the earliest Church Father to write in Latin, and who is thus widely regarded as the Father of Western (i.e., Latin) theology.

The late second-century North African teacher is important for many reasons. He argued for the truth of Christianity and the superiority of its morals over and against its pagan opponents in his Apology. In Against Marcion, Tertullian argues that the God of Israel, as seen in the Hebrew Scriptures, is both good and the same as the God of Jesus Christ. Tertullian contends that playing off “justice” against “love” (or forgiveness and grace) is a simplistic hermeneutical failure. Tertullian further criticizes Marcion for his failure to submit to the orthodox teachings of the church and for his working with a smaller-than-necessary (and mutilated, at that) canon of New Testament Scripture.

The prominence of Marcion’s teachings resulted in numerous church leaders voicing their theological disapproval, the most important of which was Tertullian’s Against Marcion.

2. Were the Christians a threat to the Roman state?

The earliest non-Jewish Christians often offended and appeared as unpatriotic threats to the fabric of society by refusing to worship the pagan gods. Given that certain gods were understood to be the protectors and sponsors of the city, failure to worship them could threaten social health and safety. Some pagans, then, engaged in sporadic and local acts of persecution and harassment of Christians, whereas others labeled Christianity as misanthropic superstition.

Within this context, we find a variety of second-century Christian responses.

The Martyrdom of Polycarp (c. 155/160)

The second century witnessed the rise of stories of the martyrdom of early Christians. The historical accuracy and the theological purpose of these is much disputed. But one of the earliest and most influential of these is also one of the most entertaining. This is the Martyrdom of Polycarp, the first text to use the word “martyr” to mean not just a “witness” (the literal meaning) but an admirable hero of the faith who willingly suffers unto death in imitation of Christ.

Polycarp was an early second century bishop in the city of Smyrna who learned the Christian faith from the apostle John. History has preserved only one letter from Polycarp (The Epistle of Polycarp to the Philippians), a letter written to the church in Philippi, exhorting them to grow in Christ-like character and especially to encourage them after the fall of one of their leaders, Valens, who has committed some type of financial sin.

It’s obvious that the author has articulated the events of Polycarp’s suffering and death within the highly theological framework of Jesus’s own arrest, trial, and death. Those responsible for arresting Polycarp attempt to persuade him to say “Caesar is Lord” and to make a sacrifice in order to save his life (Mart. Pol. 8.2). At his hearing, he is charged with “atheism” (Mart. Pol. 9.2; cf. 3:2). We might find this accusation odd today: by “atheism,” critics did not mean Christians denied the existence of all divinities, but that they scorned the gods that mattered. Justin Martyr in his First Apology (c. AD 155/157) addressed to the Roman Emperor would own the title: “Thus are we even called atheists. We do proclaim ourselves atheists as regards those whom you call gods, but not with respect to the Most True God.”³

Polycarp takes a different tack. He is commanded: “Swear by the genius of Caesar; repent; say, ‘Away with the atheists!’” In mock obedience, Polycarp faces the auditorium of pagans and declares with a wave of his hand, “Away with the atheists!” (Mart. Pol. 9.2). Thoroughly provoked, they accuse Polycarp of being “the destroyer of our gods, who teaches many not to sacrifice or to worship” (Mart. Pol. 12.2). Polycarp’s martyrdom exemplifies the battle between good and evil. His endurance and fortitude call others to maintain their loyalty to Christ in the face of opposition.

Justin Martyr (AD 105–165)

Justin Martyr penned two apologies (i.e., defenses of the Christian faith), each addressed to a Roman emperor, whereby he attempted to show that the Christians are virtuous and good citizens of the state, despite their refusal to worship the pagan deities. The conversation takes place at a philosophical level, in that Justin honors the emperor by appealing to his wisdom and sense of justice. In fact, Justin compares the persecution of Christians to the persecution of the ancient Athenian philosopher, Socrates, who likewise was accused of atheism and condemned to death for criticizing traditional polytheism. Indeed, he casts Socrates as a sort of proto-Christian who “was accused of the very crimes that are imputed to us.”⁴ In this manner, Justin Martyr found precedents for Christian behavior in Greco-Roman philosophical tradition.

3. What are the boundaries of “orthodox” Christianity?

We have already seen that Tertullian’s response to Marcion’s understanding of the identity of God in relationship to the Old Testament placed Marcion outside the boundaries of so-called orthodox Christianity, but there were a variety of other challenges Christians needed to clarify, specifically as concerns the person and work of Jesus.

The Gospel of Thomas (c. 135/200)

In the second century, we have evidence that there were a variety of people writing Gospel texts about Jesus. Sometimes, these Gospels are referred to as “apocryphal,” which, taken from the Greek (ἀπόκρυφος), means something like “hidden,” “secret,” or “closed,” and is thus the antonym of “apocalyptic,” meaning “revealed,” “unveiled,” or “open.” The word “apocrypha” is not always used negatively to refer to spurious books or books full of false teachings. For example, Athanasius of Alexandria in his Festal Letter 39 (AD 367) calls certain early Christian writings “apocryphal,” but by this he only meant they weren’t suitable to be read publicly (i.e., “openly”) in church liturgies, despite their antiquity and popularity. One could, however, enjoy them in private.

So the designation “apocryphal” can refer to a mix of books. It could refer to books that are clearly outside the boundaries of creedal Christianity. It could also refer to books that are entirely orthodox in their theology and are likely intended to convey and supplement, rather than critique or replace, the accounts in the canonical Gospels.

By far the most popular of these is The Gospel of Thomas, the earliest non-canonical Gospel. Most agree that Thomas demonstrates literary dependence on the Synoptic Gospels (or traditions) and should be dated no later than the early second century.

What do we find in this Gospel?

First, it is entirely composed of sayings of Jesus and contains no narrative whatsoever. The writing begins: “These are the secret words which the living Jesus spoke and which Didymus Judas Thomas wrote down. And he said: He who shall find the interpretation of these words shall not taste death” (Gos. Thom. 1). Readers of Thomas are intended to meditate upon Jesus’s secret words.

So, the entire Gospel is filled with ambiguous and difficult-to-interpret sayings of Jesus. The portrait of Jesus in Thomas is strikingly different from that of the canonical Gospels. In Thomas, Jesus is characterized as a wise but provocative sage whose words enable those who listen to attain knowledge. There is no hint that Jesus is the Jewish Messiah who suffers, dies, and is raised from the dead in order to save humanity. In fact, Jesus’s teachings in Thomas often contradict his teachings from the canonical Gospels. In Thomas, Jesus rejects the prophets of Israel; he overturns the necessity and importance of Torah practices such as circumcision; rejects the practices of prayer, fasting, and almsgiving; and denigrates the notion of resurrection from the dead.

Second, the Gospel of Thomas conveys entirely different notions about the person of Jesus and salvation. Instead of a Gospel that centers upon Jesus as the Messiah of Israel, sent by God in the fulfillment of his Scriptures, who calls humanity to follow him through patterning their lives after him, and who dies on the cross to save humanity from their sins, Thomas presents a radically different construal of Jesus and salvation. Instead, Jesus is an obscurantist teacher who attempts to lead people to an inner knowledge and awareness of who they are and from whence they came.

Papias of Hierapolis (AD 60–c. 130)

In the early second century, Papias, the bishop of Hierapolis, wrote five volumes titled Expositions of the Sayings of the Lord (see Papias, Fragments 3.1). Papias’s introduction to his work indicates that he focused on collecting stories and teachings about Jesus from those who were taught by eyewitnesses of Jesus’s ministry. Papias provides evidence that the stories and teachings in the canonical Gospels derive from memory—that is, the remembered and orally transmitted sayings and stories of Jesus. In his prologue to his Expositions of the Logia of the Lord, Papias describes his method in this way:

I shall not hesitate to set down for you, along with my interpretations, everything I carefully learned then from the elders and carefully remembered, guaranteeing their truth. … And if by chance someone who had been a follower of the elders should come my way, I inquired about the words of the elders—what Andrew or Peter said, or Philip, or Thomas or James, or John or Matthew or any other of the Lord’s disciples, and whatever Aristion and the elder John, the Lord’s disciples, were saying. For I did not think that information from books would profit me as much as information from a living abiding voice.⁵

Papias indicates that, even after the canonical Gospels had been written, he preferred the oral transmission of the Jesus tradition. His means of obtaining access to the Jesus tradition consists in his inquiring about “the words of the elders.” It is this later group that Papias describes as providing access, by means of their association with the Lord’s disciples, to the Jesus tradition. Papias seems to describe the transmission, then, as running as follows: Jesus → disciples/elders → group who followed the elders → Papias.

Irenaeus of Lyons (c. 155–c. 191)

Perhaps the greatest theologian of the second century, Irenaeus of Lyons develops a powerful argument for apostolic tradition and a rule of faith that would help Christians identify both what texts are scriptural as well as what groups and beliefs are outside the boundaries of orthodoxy.

Irenaeus argues that theology must be grounded in the fixed tradition of the apostolic proclamation. Of central importance for Irenaeus here is the Fourfold Gospel. There are, Irenaeus argues, four and only four Gospels that are scripturally authoritative for the worldwide church (Haer. 3.11).

The apostolic proclamation, grounded in the Fourfold Gospel, was of central importance to Irenaeus, among others, in the development of “the rule of faith.” This rule articulated the first-order theological doctrine regarding the identity of God the Father, the person of Christ, and the role of the Spirit. This rule allowed for the existence of a variety of other theological disagreements, but it provided a narrative structure for understanding the identity of God, the work of the incarnate Son of God, and the body of Christ (see Haer. 1.10.1). The rule of faith allowed Irenaeus to articulate a hermeneutical or interpretive guide to reading the Christian Scriptures that enabled the church to ensure its continuity with the original teaching of the apostles against teachings of ‘Gnostic’ Christians.

Conclusion

Two claims can be made with the utmost certainty regarding the second century.

First, early Christianity was highly textual. Just remarkably bookish. We have barely even scratched the surface in terms of describing the vibrant texts that were authored during this time period.

Second, the second century was a time of incredible importance as the church clarified its beliefs and identity with respect to the synagogue, Roman polytheism, and alternative (or “heretical”) forms of Christianity. The church would have to wait for the likes of Cyprian, Athanasius, and Augustine (among many others!) to provide theological clarity on a variety of important matters, but it is certain that they stood on the shoulders of Ignatius, Justin Martyr, Tertullian, and Irenaeus.

Share your thoughts

Do you have a favorite work by an Apostolic Father? Join us in the Word by Word group to share your thoughts.

Joshua Jipp’s recommended resources

• Bird, Michael E., and Scott Harrower, eds. A Handbook to Second-Century Christianity. Baylor University Press, 2025.
• Fredriksen, Paula. Ancient Christianities: The First Five Hundred Years. Princeton University Press, 2024.

Additional related resources

Related articles

• If the Reformers Believed in Sola Scriptura, Why Quote the Church Fathers?
• What Christians Can Learn from the Gospel of Thomas
• Why You Should Read Irenaeus of Lyons
• Know Your Heresies: How Not to Be a Heretic
• 14 Books on Church History: A Guide to Your Spiritual Heritage

1. I.e., Clement of Rome, Polycarp’s Epistle to the Philippians, The Shepherd of Hermas, and the Epistle to Diognetus.
2. I am using the translation of Michael W. Holmes, The Apostolic Fathers in English, 2nd ed. (Baker Academic, 1999). You can purchase the bilingual edition, which features both Holmes’s celebrated English translation alongside the original Greek or Latin, in the Logos Store: Michael W. Holmes, The Apostolic Fathers: Greek Text and English Translation, 3rd ed. (Baker Academic, 2007).
3. Justin Martyr, First Apology 6, in The Fathers of the Church 6, trans. Thomas B. Falls (Catholic University of America, 1948).
4. Justin Martyr, Second Apology 10, in The Fathers of the Church 6, trans. Thomas B. Falls (Catholic University of America, 1948).
5. Papias, Fragments 3–4, in The Didache, The Epistle of Barnabas, The Epistles and the Martyrdom of St. Polycarp, The Fragments of Papias and The Epistle to Diognetus, trans. James A. Kleist (Newman, 1948).