The Demonstration of the Apostolic Preaching

St. Irenaeus of Lyons

About this writing. Alongside his great five-book refutation Against Heresies, St Irenaeus of Lyons (c. 130 – c. 202) wrote a shorter, constructive work — a Demonstration (or Proof) of the Apostolic Preaching, addressed to a friend named Marcianus. Eusebius knew of it, but the text itself was lost for some seventeen centuries until an Armenian manuscript was rediscovered in 1904 and first published in 1907. It is the earliest surviving example of a Christian catechism or handbook of the faith.

The work falls into two parts. The first (roughly sections 1–42) sets out the “rule of faith” — the one God the Father, His Son Jesus Christ, and the Holy Spirit — and traces the divine economy from creation and the fall through the patriarchs. The second (sections 43–100) is a sustained demonstration that the whole of the Gospel was foretold in the Old Testament, marshalling the prophets to prove Christ’s incarnation, cross, resurrection, and the calling of the nations. Irenaeus’s aim is pastoral: to confirm a believer’s faith and equip him to recognise and refute error.

The translation is that of J. Armitage Robinson (1920), made from the Armenian and now in the public domain. The sections are numbered 1–100 following the standard editions.

Chapter 1
Chapter 2
Chapter 3
Chapter 4
Chapter 5
Chapter 6
Chapter 7
Chapter 8
Chapter 9
Chapter 10
Chapter 11
Chapter 12
Chapter 13
Chapter 14
Chapter 15
Chapter 16
Chapter 17
Chapter 18
Chapter 19
Chapter 20
Chapter 21
Chapter 22
Chapter 23
Chapter 24
Chapter 25
Chapter 26
Chapter 27
Chapter 28
Chapter 29
Chapter 30
Chapter 31
Chapter 32
Chapter 33
Chapter 34
Chapter 35
Chapter 36
Chapter 37
Chapter 38
Chapter 39
Chapter 40
Chapter 41
Chapter 42
Chapter 43
Chapter 44
Chapter 45
Chapter 46
Chapter 47
Chapter 48
Chapter 49
Chapter 50
Chapter 51
Chapter 52
Chapter 53
Chapter 54
Chapter 55
Chapter 56
Chapter 57
Chapter 58
Chapter 59
Chapter 60
Chapter 61
Chapter 62
Chapter 63
Chapter 64
Chapter 65
Chapter 66
Chapter 67
Chapter 68
Chapter 69
Chapter 70
Chapter 71
Chapter 72
Chapter 73
Chapter 74
Chapter 75
Chapter 76
Chapter 77
Chapter 78
Chapter 79
Chapter 80
Chapter 81
Chapter 82
Chapter 83
Chapter 84
Chapter 85
Chapter 86
Chapter 87
Chapter 88
Chapter 89
Chapter 90
Chapter 91
Chapter 92
Chapter 93
Chapter 94
Chapter 95
Chapter 96
Chapter 97
Chapter 98
Chapter 99
Chapter 100

Knowing, my beloved Marcianus, your desire to walk in godliness, which alone leads man to life eternal, I rejoice with you and make my prayer that you may preserve your faith entire and so be pleasing to God who made you. Would that it were possible for us to be always together, to help each other and to lighten the labour of our earthly life by continual discourse together on the things that profit. But, since at this present time we are parted from one another in the body, yet according to our power we will not fail to speak with you a little by writing, and to show forth in brief the preaching of the truth for the confirmation of your faith. We send you as it were a manual of essentials, that by little you may attain to much, learning in short space all the members of the body of the truth, and receiving in brief the demonstration of the things of God. So shall it be fruitful to your own salvation, and you shall put to shame all who inculcate falsehood, and bring with all confidence our sound and pure teaching to everyone who desires to understand it. For one is the way leading upwards for all who see, lightened with heavenly light: but many and dark and contrary are the ways of them that see not. This way leads to the kingdom of heaven, uniting man to God: but those ways bring down to death, separating man from God. Wherefore it is needful for you and for all who care for their own salvation to make your course unswerving, firm and sure by means of faith, that you falter not, nor be retarded and detained in material desires, nor turn aside and wander from the right.