A conference in Dublin this coming weekend is intended to heighten public awareness of a jewel in the crown of the remarkable collection which is the Chester Beatty gospel papyri. Or P45 to give them their official scholarly designation.

They form a substantial part of one of the earliest known codices of the four gospels, dating from the third century (circa AD 250) and are a direct link with the Christian Church while it was still a persecuted sect within the Roman empire.

They also put us in touch with the earliest period of a movement destined to shape much of Western and global civilisation.

The papyri are then cultural artefacts of the highest significance, of interest to the concerned secularist as well as being worthy of respect from the committed Christian.

Like all such artefacts, the papyri call for contextualisation within their own world if their significance for ours is to be properly assessed. Jesus and the first Christians were heirs to the tradition of the Torah as a written collection of Israel's sacred writings. Yet, unlike some other Jewish reform movements, such as the Essenes whose library is now known from the Dead Sea Scrolls, the early Christians were not a scholastic community.

Jesus's Pharisee opponents accused him of being "unschooled" (John 7, 15). His earliest followers were described as "ignorant" and "illiterate" (Acts of the Apostles 4,13). But it is important to judge these statements as vilification by the small literate elite in Jerusalem.

True, Paul used letter-writing as a way of communicating with the communities he had established in various cities, and a collection of his letters must have been made shortly after his death. An early version of this is also represented in the Chester Beatty collection (P46). The case of Paul indicates a shift in the social standing and urban context of some at least of his new converts, as distinct from Jesus's own ministry which was largely concentrated on the rural villagers of Galilee. Yet even Paul insists that his preference was for the spoken rather than the written word.

The impulse to produce a narrative account of Jesus's life and ministry was probably due to liturgical and catechetical needs, the death of the eyewitnesses to Jesus's life and the shift from the Aramaic-speaking oral culture to the Greek-speaking urban world of the Pauline mission. In that circle history-writing and biography were well-established literary genres. So it was necessary to produce "an accurate account of all that has been accomplished among us, as these were handed on by those who from the beginning were eyewitnesses and ministers of the Word" (Luke 1, 1-4).

This statement echoes the literary practices of contemporary Greco-Roman historians and no doubt helped to maintain the credibility of the movement among its pagan competitors.

Unlike its Jewish precursors, the early Christians adopted a relatively novel form of the codex or book rather than the scroll for practical reasons such as travel and portability, but also probably for ideological reasons to emphasise its separateness from the parent religion.

Modern scholarship has highlighted the fact that several different "lives" of Jesus were produced with considerable variations even among the so-called synoptic gospels (i.e. Matthew, Mark and Luke) which shared the common pool of stories and sayings of Jesus that had circulated orally from the very beginning. John's gospel has always been recognised as being quite different in tone and emphasis.

There were also the gospels of Thomas, Peter and Mary, as well as gospels attributed to dissident groups such as the Ebionites and the Gnostics. Evidence points to the fourfold gospel, comprising our canonical ones, establishing themselves relatively early as authoritative, probably because they were attributed to known disciples of Jesus (Matthew and John) or to those closely associated with that circle (Mark/Peter and Luke/Paul). It was this development that gave rise to the production of codices such as the Chester Beatty one, containing the four gospels as well as Acts of the Apostles in one book.

Despite some recent attempts to rehabilitate the other gospels, the likelihood is that they were derivative and in several respects were regarded as not conforming to an emerging orthodoxy.

So, towards the end of the second century the gospel of Peter was in circulation in Antioch. The earliest commentators on this fourfold gospel, such as Justin Martyr (died circa AD 165) and Irenaeus of Lyon (died circa AD 200), were conscious of the differences between the individual accounts, possibly because pagan critics had sought to discredit them on the basis of these seeming discrepancies. Yet these first apologists stressed the deeper unity that existed between them, based on the one Spirit "that bound them together".

Thus, both writers prefer to speak of the Gospel rather than gospels (plural), and Irenaeus goes to great pains to justify the fourfold gospel in terms of the four cardinal points of the compass, implying the universality of the message they contained. This message was Gospel, "good news" about Jesus Christ as God's final word for the human family, a conviction which had driven the movement from its inception, as Paul already emphasised for his Galatian converts. There is only one gospel, he writes, and if "I myself, or an angel from heaven were to preach another, we should be anathema" (Galatians 1, 8).

Others were less sure about the fourfold gospel and its unity as seen by Justin and Irenaeus. The Chester Beatty collection contains another highly significant manuscript, the only extant version in the original Syriac of a commentary on a second-century gospel harmony, the Diates- saron, compiled by a Syrian monk, Tatian, about AD 175.

Apparently troubled by the discrepancies in the gospels he sought to harmonise the four into one account (hence the Greek name). His concerns were, therefore, more historical than theological, probably because of his desire to present a single coherent account of the "life" of Jesus to counteract the pagan despisers. Its importance lies in the fact that not all in the new movement shared the theological conviction that lay behind the fourfold gospel, faced with the historical difficulties posed by their differences.

Tatian's concerns had to await the 18th-century Enlightenment's preoccupation with history before they would be addressed again. Indeed they are still very much at the centre of Gospel studies to this day.

There is then a seeming paradox at the heart of the early Christian self-understanding as this was expressed in the fourfold gospel.

The good news is indeed one, yet its human expressions can be varied. The Word of God can never be exhausted or fully represented in the words of humans. It is for this reason that early Christian writers sought to compare the Scriptures with the Incarnation: one was the written Word of God, the other was the Word made flesh. Both modes, the written and the enfleshed, reveal and conceal the mystery of the divine love for the world.

Human language, like human life, is always culturally and historically conditioned, a partial and imperfect expression of the deeper meaning of things. It calls for a special attuning of the ear to hear that deeper voice, the lectio divina of Christian worship and prayer.

The recognition of the limits of life and language allowed Irenaeus and others after him to imagine the Christ in glory with four faces, each painted by a different evangelist. My own favourite expression of this profound idea is that of the 13thcentury Window of the Evangelists at Chartres Cathedral outside Paris.

The central axis of the depiction consists of the Virgin and child at the lower level (the Word made flesh), while the glorious risen Christ surrounded by the 12 apostles occupies the upper, rose section, directly above.

On either side of the Virgin and child are two panels, each containing a giant figure carrying a dwarf on his shoulders with an orientation towards the rose centre. What is utterly surprising about this portrayal is that the evangelists are depicted as the dwarfs and the Old Testament prophets as the giants, thus giving expression to a famous medieval saying that "we are like dwarfs on the shoulders of the giants of the past; we can see farther because we are raised higher".

Each of the evangelists has his own giant, allowing him to see Christ in a distinctive fashion. And yet, despite the diversity of perspective which the different panels suggest, the whole window has a harmonious unity that encapsulates the Christian story of the one and fourfold gospel, and its indebtedness to its Israelite precursors.

Insofar as we can ascertain, Christianity came to Ireland almost two centuries after the production, probably in Egypt, of the Beatty Codex. By then it had become the official religion of Empire, and the urgency was to spread the gospel to the very outer regions of the known world.

At the other end of Dame Street in Trinity College, the great uncial manuscript of the Book of Kells bears witness to this "triumph" of Christianity with its elaborate illumination and highly decorative calligraphy.

By contrast, the Beatty Codex was written in small script by a not-very-elegant hand and without any illumination. It is written on papyrus, not vellum, and each sheet is folded in two to economise and fit in all four gospels in a codex of manageable proportions. This contrast between the styles and execution of the two codices tells its own story of two very different moments in early Christian self-expression - the struggle for survival in a hostile environment and the high culture of triumphant Christendom.

At the beginning of this third millennium by Christian reckoning, Christendom, as the unified world of Church and Empire, is now no longer a reality, even in Ireland, where, ironically, it survived longer than within its original boundaries on mainland Europe.

As we search for ways of rescuing some of the more important gospel values that shaped our culture from the jaws of the Celtic Tiger we might spare a thought for the moment represented by the Beatty Codex. The pioneering spirit of those who produced it and dared to live their lives by its message could serve us well today.

Sean Freyne is Professor of Theology, Trinity College and a Trustee of the Chester Beatty Library. Among his publications dealing with the gospels are Galilee, Jesus and the Gospels. Literary Approaches and Historical Investigations (1988) and Galilee and Gospel. Collected Essays (2000).