In this essay, I will argue that it does indeed make sense to talk of Christian Orthodoxy before Constantine. There is a clear ‘true and life-giving faith, which the Church received from the apostles and which She transmits to her children’ united as one Eucharistic communion. This essay will highlight that Christian Orthodoxy is ensured and safeguarded in the early Church, by the Eucharist itself, which preserves the true faith and unity within the one body of Christ. Firstly, I will introduce Irenaeus’ writings which discern Orthodoxy, by the unbreakable and infallible holy apostolic Tradition of the Church – explaining that this Tradition is the deposit of the Holy Spirit through time. This will lead to my discussion on the Eucharistic assembly of Christ, being the eternal communion of the Church that keeps Her united, as one faith and one body.
Perhaps the most obvious place in which we may discern the presence of the notion of Orthodoxy in early patristic literature, is in the writings of St Irenaeus of Lyon, in the year 180AD:
‘All who wish to see the truth have at hand and can perceive the tradition of the apostles made manifest in all the world in the whole Church and we are able to enumerate those who were appointed bishops in the churches by the apostles and their successors down to our time..’
Irenaeus highlights that Orthodoxy is ensured through apostolic succession – in that the correct and holy teaching of the Church is handed down from generation to generation, through the Holy Spirit. He has this clear concept of Orthodoxy, and from this concept it is therefore possible to speak about Christian Orthodoxy in the early Church. This holy Tradition preserves the Church’s validity and apostolicity – guarding it from heresy. Irenaeus believes in ‘One Holy Catholic and Apostolic Church’ (which is proclaimed in the Nicene Creed, over 100 years later at the First Ecumenical Council) telling us that ‘the Church, having received this preaching, and this faith, although scattered throughout the whole world, yet, as if occupying but one house, carefully preserves it. She also believes these points of doctrine just as if she had but one soul.’
In this period, the Church, as one body (1 Cor 12:27) proclaims the one Gospel of truth in unity and harmony, regardless of location – as it continues to do so today. The Early Church’s members ‘were encouraged to think of themselves as an extended family’ – all ‘one in Christ Jesus.’ (Gal 3:28) The fact that several doctrines had not yet been officially clarified and refined in the early Church, is simply an issue of time and theological discussion. ‘It was the development and refinement of these proper beliefs ( referring to the apostolic teachings and tradition in the Early Church) that ultimately led to the orthodox doctrine of Christ as fully God and fully man..and to the doctrine of the Trinity.’ These refinements and clarifications gradually took place through the life of the Church, especially in reply to heresies – however the fundamental Orthodox faith is founded upon and derives from Christ Himself, through His apostles on Pentecost. Orthodoxy (meaning correct faith and worship) is passed on by the Holy Spirit, which is bestowed upon the apostles, through to the early Church and its bishops. This can be seen through the Church’s consistency during this period, as the Holy and Life-Giving Spirit is deposited to the teachers, martyrs and saints. (1 Cor 12:28) Founded by Christ and His apostles, the Church is indeed Orthodox as it carries and bears the right doctrines, the true teaching and worship. ‘For where the Church is, there is the Spirit of God; and where the Spirit of God is, there is the Church, and every kind of grace; but the Spirit is truth.’
The apostles of Christ, who ‘were filled with the Holy Spirit’ (Acts 2:4) through to today’s bishops, do not simply possess authority but also charisma by virtue of their ordination. Clement introduces us to this process, as ‘God sends Christ – Christ sends the apostles – the apostles transmit the message of Christ’ by establishing the visible Church. The bishops uphold and carry the Orthodox faith with them in the early Church, and Saint Ignatius of Antioch emphasises their great importance. ‘As many as are of God and of Jesus Christ are the bishop’ for the bishops who are successors of the holy apostles, are representatives of Christ Himself. The bishop therefore validates the Eucharist and the preaching of the Orthodox faith, and through the bishop’s consent and blessing the Church is able to carry out its work and mission in this period of growth. ‘Do nothing without the bishop.’
‘Following the instruction of our Lord Jesus Christ..the apostles went with the assurance of the Holy Spirit to announce everywhere the good news of the coming of the Kingdom of Heaven. In the various villages and cities they proclaimed the word..and established bishops and deacons (Επισκόπους και Διακόνους) for the future believers.’
We may ask ourselves why this Holy Tradition, (the deposit of the Holy Spirit) passed on through time, is so important, and what connection it has to being sure of Christian Orthodoxy? Is this apostolic Tradition, which Irenaeus promotes, necessarily scriptural? ‘It is clear that the deposit of the Tradition which was revealed to the prophets in the Old Testament, was consecrated in the incarnation of the Word, and is active in the purification, illumination and theosis of the faithful in the Church.’ The Holy Tradition is not separate or different from the Holy Scriptures – but is contained in them, and is identical to the entire manifestation of the Church. The Tradition, and the deposit of true faith only exists within the Church – as Christ is the vine in which the branches abide and bear fruit. For this reason Christ is fully present and can be understood within the Holy Scriptures, only when we read and interpret them within the Church. This is why Irenaeus argues that those who turn away from Christ’s Church, and its holy apostolic tradition ‘are neither nourished into life..nor do they enjoy that most limpid fountain which issues from the body of Christ; but they dig for themselves broken cisterns (Jer 2:13) out of earthly trenches..fleeing from the faith of the Church..rejecting the Spirit, that they may not be instructed.’ 
Throughout history, heresies have often appeared from certain individuals who, rather egoistically, believe that they are being called to, and chosen for a certain position, in order to share their personal ideas and views. Irenaeus warns us of this and tells us that we must not seek truth from individuals, but from the divine proof of the Church, ‘since the apostles, like a rich man depositing his money in a bank, delivered into her hands in the fullest measure the whole truth: so that every man, whosoever will, can draw from her the water of life.’
This Orthodox unity which is being spoken of in this period’s patristic writings is not only a visible, historical unity, but primarily a Eucharistic unity. The Church is united in communion ‘as we are one’ (John 17:11). It is the Eucharistic unity that refutes and surpasses the ideas of separation and antagonism between the early Christian groups (for example various pagan converts, alongside Jewish Christian groups). ‘Only if we regard the Eucharist as the revelation of the Church in her ideal and historical unity, and the bishop first and foremost as the leader and head of the eucharist assembly which unites the Church of God in space and time, do we recognise in each of these their profound ecclesiological content.’ Rather than viewing the Eucharist as simply one of the seven sacraments, and simply a means to salvation, Zizioulas highlights that it is indeed ‘the very expression of salvation which essentially consists in the union of man with God and Christ.’ This is the true eternal unity of the Church, which can be seen in this early period. The unity of faith is a presupposition of this greater Eucharistic unity. If the various Christians and churches do not recognise themselves as united in faith, they would not have been united in communion. ‘Only during the sacrament of the divine Eucharist do we have a certain perceptible portrayal of the mystic union and incorporation of Christ with the faithful members of His body who are in communion with Him.’ Not only is the early Church united by an abstract isomorphism of beliefs, but when we speak of Orthodoxy we are talking about true, real-life unity in Christ.
This can be seen by looking at the worship of the early Church. Worship, of course, consists of prayers, scriptural readings and hymns – however at the centre of it all is the ‘Giving Thanks,’ (Ευχαριστία). ‘And they devoted themselves to the apostles’ teaching and fellowship, to the breaking of bread.’(Acts 2:42) Regular participation in the Eucharistic meal 'was a hallmark of the earliest communities.’ The Eucharistic celebration, because it is the communion of the united body of Christ, is only partaken by baptised followers of the Lord in the early Church. The Eucharist gathers all Christians into one heavenly assembly, reflecting the Kingdom of God. (Heb 12:22-24) For this reason, confession and reconciliation precedes the celebration, as communion in Christ means love. In fact during this period, the fellowship meal is referred to as ‘Αγάπη’ – divine love. It is the ‘Φάρμακον Αθανασίας,’ and ‘love incorruptible.’
Although early Christian worship takes place in various communities and in family homes, the participation in the ‘eschatological banquet in which Jesus and his followers would share when he returns in glory’ means that the whole Church comes together, receiving the ‘body and blood of the Lord’ (1 Cor 11:27) in communion, in a united orthodox faith, and in love. ‘The Church has always felt herself united..in faith, in love, in the one baptism, in the holiness of life’ but of course all these things are ‘incorporated in the Eucharist.’
Regardless of background or location, the early Church is seen to be one family in Christ – who share in the one Orthodox faith, and in the Eucharistic cup of salvation and love. The early fathers of the Church emphasise that the union and equality of Jewish and Gentile Christian believers is this mystery which is revealed in the Gospel. ‘There is one body and one spirit…one Lord, one faith, one baptism, one God and Father of all, who is over all, and through all, and in all.’
To conclude, I have shown through the writings of Irenaeus and other early fathers, as well as from the holy Scriptures and other sources, that it does make sense to talk of Christian Orthodoxy before Constantine – within the one Eucharistic body of Christ, through its Holy apostolic Tradition.
A New Eusebius, 1987, London:SPCK, p 109-118.
Davidson, I, 2005, The Birth of the Church, Oxford:Monarch Books, 112.
Ehrman,B 2003, Lost Christianities, Oxford:OUP, 151.
Karmiris,J 1960, Summary of the Dogmatics of the Orthodox Catholic Church (in Greek), 80.
Mackinnon, J 1936, From Christ to Constantine, London:Longmans,214-215.
Romanides, J 2004, An Outline of Orthodox Patristic Dogmatics, Rollinsford:ORI, 89-91.
Zizioulas, J 1985, Being as Communion, London : DLT , p. 173.
Zizioulas, J 2001, Eucharist, Bishop, Church, Boston:Holy Cross Orthodox Press, Introduction.
 Irenaeus, Against Heresies III.1.
 Irenaeus, I.3
 Ivor J.Davidson, The Birth of the Church (Oxford:Monarch Books, 2005) 112.
 Bart D.Ehrman, Lost Christianities (Oxford:OUP, 2003) 151.
 Irenaeus, III.38.I
 John Zizioulas, Being as Communion (London:DLT, 2004) 173.
 I Clement 42:2-4.
 John Romanides, An Outline of Orthodox Patristic Dogmatics (Rollinsford:ORI,2004) 89-90.
 Romanides, An Outline of Orthodox Patristic Dogmatics, 89-91.
 Irenaeus, III.38.I
 Irenaeus, III.4.1
 John Zizioulas, Eucharist, Bishop, Church (Boston:Holy Cross Orthodox Press, 2001) Introduction.
 Zizioulas, Eucharist, Bishop, Church, Introduction.
 Karmiris, Summary of the Dogmatics of the Orthodox Catholic Church (in Greek), (1960) 80.
 Davidson, The Birth of the Church, 117-120.
 Davidson, The Birth of the Church, 121.
 Davidson, The Birth of the Church, 122.
 Zizioulas, Eucharist, Bishop, Church, Introduction.
 James Mackinnon, From Christ to Constantine (London:Longmans,1936) 214-215.