Teresa Morgan looks at a surprising shift in early Christian faith

The concept of ‘faith’ (pistis or fides in the languages that dominate early Christian writing) has been central to Christianity for longer than its recorded history. No idea is invoked more often, from the earliest letters of Paul onwards. Within a few years of the crucifixion, Christians were calling themselves ‘the faithful’. By the turn of the first century they were calling Christianity ‘the faith’. By the fourth century, ‘faith’ had become a uniquely complex concept in ancient religiosity, encompassing trust, belief, knowledge, fideism (the ‘leap of faith’), confidence, hope, prayer, and worship.

The most famous definition of faith appears in Augustine’s On the Trinity (13.2.5). Augustine distinguishes fides quae (‘the faith which is believed’ i.e. the content of doctrine), from fides qua (‘the faith by which it is believed’, what takes place in the mind and heart of believers). This is not an ideal definition: it underplays the relational aspect of faith and ignores the meaning ‘the faith’. In Augustinian terms, however, this essay considers one aspect of fides qua: how, between the second and fourth centuries, belief gradually took over from trust as a key aspect of Christian pistis/fides.

Belief that certain things are true forms part of Christian thinking from as far back as we can trace. In 1 Corinthians 15.3–11, written in the early 50s, Paul tells the Corinthians, ‘I handed on to you as of first importance what I also received: that Christ died for our sins in accordance with the scriptures; that he was buried; that he was raised … so we preach and so you believed (οὕτως κηρύσσομεν καὶ οὕτως ἐπιστεύσατε).’ For very early Christians, however, it was not believing itself that admitted one to the community or kept one there. That took a further step: putting one’s trust in God and Christ.

This distinction should come as no surprise to classicists. Under the Roman empire, most people believed in the existence of a vast number of gods, heroes, divine men, demons and so on. Nobody worshipped them all, not least because many were specific to a particular place or social group or had a limited sphere of action. (Whether all Jews were strictly monotheistic in this period is debated, but believing e.g. that other supernatural powers existed or that Enoch had been taken up to heaven would not necessarily entail worship.) In Christian contexts, the distinction between belief and religious commitment is less obvious in Greek than in English, because the verb Christians most often use for committing to God and Christ, pisteuein, can mean both ‘believe’ and ‘trust’. In context, however, it is normally clear which is in play. Early writers undoubtedly expect Christians to believe certain things about God, Jesus Christ, and God’s action in the world, but when they call them to commit to God and Christ, they use pisteuein in the sense of ‘trust’.

Early Christian writing has very little interest in belief. Gospels, collections of sayings, acts, apocalypses, letters, hymns, prayers, spells, and sermons—all use pistis language, but nearly always in a relational sense. When early writers talk about belief, they tend to use not pisteuein but nomizein, dokein, gnōsis, phronēsis, putare, noscere, opinio—which is why we speak of ‘orthodoxy’ not ‘orthopisty’. From around the mid-second century, however, some Christians become increasingly interested in belief, either in the context of wrangles among the faithful about what to believe, or in debates with non-Christians. Some of these begin to use pisteuein to refer to belief. There are two likely reasons for this shift. One is what we might call ‘concept creep’: Christians are so invested in pistis/fides language that, over time, they apply it to more and more aspects of the faith, and since ‘belief’ is a possible meaning of pistis and fides, it is there to be used. The other is the influence of Platonism.

Plato and his followers use pistis atypically, among Greek-speakers, to refer to beliefs which are based on the evidence of this world – which, in their view, are unreliable compared with knowledge of the world of ideas. In the later Hellenistic world, however, we encounter a number of intellectuals influenced by Platonism (including Cicero and Plutarch) who are also deeply interested in mainstream cult. Plato’s specialized use of pistis creates a difficulty for them, because mainstream cult involves beliefs about the gods which are based on this-worldly evidence such as the fulfilment of prophecy and the successes of the gods in healing people or ending wars. Many middle-Platonistsare concerned to defend this-worldly reasons for believing certain things about the gods, and, because of their debt to Plato, they often use pistis/fides language to do so. Early Christians are also keen to defend their cult against accusations that it is irrational, and some of these discuss Christian pistis in terms increasingly influenced by Platonism.

Justin Martyr was born in about 100 CE. In the Dialogue with Trypho he describes how, as a young man, he investigated several schools of philosophy, including Platonism, before discovering and converting to Christianity. In the 150s Justin composed an apology, addressed to the imperial household, defending Christianity against contemporary accusations that it was immoral, irrational, and seditious. Most of his defence of Christianity’s rationality is couched in the language of thought and knowledge, but occasionally he uses pistis language, in very much the way that religious middle-Platonists use it, to suggest that there are this-worldly bases on which it is rational to believe:

We have received, by tradition, that God does not need the material offerings that human beings can give, seeing that he himself provides [us with] everything. We have been taught, and persuaded, and believe (δεδιδάγμεθα καὶ πεπείσμεθα καὶ πιστεύομεν) that he accepts solely those who imitate the good things which pertain to him: temperance, justice, and philanthropy …

The coming into being at first was not in our power; and in order that we may follow those things that please him, choosing them by the powers of reason which he has given us, he persuades us and leads us to pistis (πείθει τε και εἰς πίστιν ἄγει ἡμᾶς). (10.60-1, 63)

The idea that we please God by deploying the reason God has given us and imitating the divine virtues, and that we can do this because of the teaching we have received, parallels contemporary middle-Platonism (and, indeed, Stoicism). Justin does not define what he means by Christian pistis, but by linking it twice with persuasion he implies that it is the outcome of teaching applied to reason, and therefore that it is something like belief.This image has an empty alt attribute; its file name is picture1.jpg

Justin Martyr (wikipedia image)

A generation later, another apologist goes a little further. Athenagoras of Athens (born ca 133) was also a philosopher, probably a Platonist, and a Christian convert. His Apology, addressed to the Emperor Marcus Aurelius and dated to 176–7,is a plea for equal rights. Like Justin, Athenagoras claims that Christians are moral people and loyal subjects of the emperor, and his Apology also uses mainly the language of thought and knowledge rather than that of pistis. In one passage, however, he claims that Christians share many of their views with poets and philosophers, including that, ultimately, there is only one God. This being the case, it is outrageous that Christians, uniquely, are accused of atheism and challenged ‘to prove what we think and have rightly believed (ὅ τι καὶ νοοῦμεν καὶ ὀρθῶς πεπιστεύκαμεν), that there is one God…’ (7.27).

‘What we think and rightly believe’ is a telling phrase. From the second century onwards, Christians were accused by critics of urging converts, ‘Do not think, just believe’ (e.g. Origen, Against Celsus 1.9). Athenagoras insists that Christians both think and believe, echoing a phrase, pistis orthē, ‘right belief’, which goes back to Plato’s Republic (10.601e). For Plato, ‘right belief’ has useful qualities but is inferior to knowledge. Later Platonists, however, use pistis orthē approvingly, of right beliefs or opinions which are appropriately held by those who are in a process of gaining knowledge of the divine. Athenagoras therefore implies that Christian pistis is part of a thought process about the divine which philosophers share and which leads to knowledge. To claim this, however, he has to present Christian pistis as belief, rather than, for instance, as trust.

A generation later again, Clement of Alexandria takes a deep interest in pistis, especially in his monumental Stromateis (‘Miscellanies’)His contribution to the evolution of Christian understanding of pistis is huge: partly because he is a serious philosopher, and partly because he profoundly respects the letters of Paul, and seeks to use philosophy to interpret Paul.  

Clement develops a multi-stage theory of pistis. At its simplest, it can be the kind of pre-rational trust or belief in ordinary things which all human beings practise every day (e.g. Stromateis 1.6.27). At a higher level, it is a belief-response to things that are self-evident to reason. By building on this kind of belief with rational enquiry, we begin to understand and know God, and to be able to judge the truth of claims about God (2.2, 5.1). This leads to a further level of pistis: that which we have in the truth of something which has been demonstrated by reason. This highest level of pistis is almost indistinguishable from gnosis, knowledge of God and even (in Platonic fashion) assimilation to God (7.10.55, 57).

Clement makes the most sustained early attempt to syncretize Christianity and Platonic philosophy, and in the process he makes belief central to pistis. He is followed, among others, by his fellow Alexandrian Origen, in his invective Against Celsus. Origen shares Clement’s view that faith and reason are symbiotic, but is also conscious of the limitations of reason. We deal with this, he suggests, by exercising pistis in the sense of rational risk. Every day, when we go to sea or plant our fields, we trust that what we do will turn out well (1.11, 3.39). We trust in God in the same way, and this is appropriate because risk-based trust is rational (1.11). There is always a gap between what we can infer from evidence and the uncertain future, and trust leaps into that gap.

In a sense, here, Origen is talking about a ‘leap of faith’, but not in the modern sense. He advocates not deliberately non-rational trust or belief, but trust as a rational risk. By making this argument, however, Origen highlights the cognitive element even in trust, and shifts the centre of gravity of Christian pistis further towards believing.

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Dutch Illustration showing Origen teaching his students (Jan Luyken 1700: wikipedia)

All these writers are encouraged by interactions with non-Christians to present belief as central to Christian pistis. At the same time, some Christians are pushed in the same direction by a different set of conflicts: disputes among the faithful about their understanding of God and Christ. One example will have to suffice.

It is a surprising fact, in view of later Christian history, that, as far as we can tell, the first Christians to be expelled from their churches for believing (what their bishop regarded as) the wrong thing were Valentinus and Marcion, in the mid-second century (Tertullian, Prescription against Heresies 30.2:  one could be expelled earlier for other things, such as idolatry or immorality.) In Against Marcion, Tertullian introduces Marcion as ‘a monster more philosophical than Christian. Diogenes the Cynic used to go about, with a lantern, at midday, looking for a real man, but Marcion has lost the God whom he had found by dousing the light of his faith (extincto lumine fidei suae)’ (1.1.5). Marcion, in Tertullian’s view, holds wrong views about God and the nature of Christ. The ‘light of faith’, which ought to guide Marcion to God, is therefore what he thinks is true about God and Christ.

This makes right belief foundational to fides, but not necessarily identical with it.In On the Flesh of Christ, however, Tertullian goes further.Marcion holds that it is irrational to think of God as taking on human flesh. Tertullian objects that it is only irrational in human reason. He appeals to 1 Corinthians 1.25: ‘the foolishness of God is wiser than human wisdom’. He concludes, ‘You [Marcion] are not a Christian, because you do not believe what, being believed, makes people Christians (non es Christianus, non credendo quod creditum Christianos facit)’ (2.4). In this move, Tertullian identifies being a Christian with believing that certain things are true.

Christianity is often seen as a religion centrally concerned with belief and orthodoxy – not least in contrast with Greek and Roman cult, which we tend to think of as more concerned with right ritual. Ironically, the reverse may be closer to the truth. Christians’ focus on belief, in large part, is a legacy from devout polytheists influenced by Platonism, who, by criticizing Christianity for irrationality, shifted Christianity’s focus from trust-pistis towards belief-pistis. Even then, it would take rather longer for the public affirmation of beliefs formally to define Christians. The creed which was created and validated by the Council of Nicaea in 325 was the first affirmation of faith explicitly designed to express agreed beliefs, and used both to baptize and to assess the orthodoxy of existing Christians. From 325, Christian faith really was centrally a matter of right belief.This image has an empty alt attribute; its file name is capture.jpg

Professor Teresa Morgan is a fellow and tutor of Oriel College, Oxford where she teaches Ancient History from the 8th century BC right up to the Byzantine era, and is McDonald-Agape Professor-elect of New Testament and Early Christianity at Yale Divinity School.  She has published widely in the field of Ancient History and the Early Church, with books including: Roman Faith and Christian Faith: Pistis and Fides in the Early Roman Empire and Early Churches (Oxford University Press, 2017), Popular Morality in the Early Roman Empire (Cambridge, 2010), and most recently Being in Christ in the Letters of Paul (Mohr Siebeck, 2020).