Catholics have over the years tried to debunk Irenaeus’ claim in in Against Heresies Book 2 Chapter 22 that Jesus lived to be about 50 years old. Why? Because Irenaeus invoked both Scripture and extra-biblical tradition to prove that Jesus “ was an old man for old men, that He might be a perfect Master for all, not merely as respects the setting forth of the truth, but also as regards age.Obviously, this false teaching on Irenaeus’ part shows that, even as early as the second century, traditions can be made-up and staunch defenders of the Church are not superintended by the Spirit in which they can avoid botching Biblical interpretations.

Ed: This article was made when I was a Protestant and upon greater learning and reflection my thoughts may have evolved. My more mature thoughts are here.

And, if this can happen as early as the second century with a saint, what guarantee do we have that well meaning men have not erred when relaying traditions such as the bodily assumption of Mary (first written in the 6th) or the interpretation of Petrine Primacy in Matt 16:18 (4th Century, excluding Tertullian)?

While Irenaeus’ words in AH 2.22.4-6 are so clear that it really does not require finding any more evidence that he was wrong about Jesus’ lifespan, what the heck, let’s go over some more evidence that Irenaues said what he meant and meant what he said.

Debunking the counter argument that Irenaeus thought Jesus was born during 14 AD. If we look at how Irenaeus’ dates Jesus’ life, we can see that Christ lived for at least 45 years. Obviously, Catholics have a vested interest in devising an apologetic that does not allow this. Let’s quote a Catholic named Craig Ostrowski, as he brings up the relevant texts that he believes defends the Catholic position, yet when properly interpreted actually eviscerate it:

In Against Heresies 3.21.3 he wrote that “our Lord was born about the forty-first year of the reign of Augustus.” This would place the birth of Christ, according to Irenaeus, in 14 A.D.. While this year does not fall within the range commonly accepted, it is, nevertheless, interesting because of how Irenaeus dates the crucifixion. In The Demonstration of the Apostolic Preaching 74 he writes that “Pontius Pilate, the governor of Claudius Caesar… condemned Him to be crucified.” Since Claudius ruled from 41 to 54 A.D. that would place the age of Jesus anywhere from 27 to 40 years old. Obviously the age of 33 years falls well within that range.

Taken at face value, it would appear that Irenaeus did not make a huge historical blunder. Augustus Caesar became the Roman emperor in 27 BC and reigned a little less than 41 years. He did not have a 41st year of reign by this count, but if he did (as ancient writers sometimes get their dates a little off) his 41st year of rule would have been between 14-15 AD.

However, if we go by other church fathers, we will realize that they were counting the beginning of Augustus’ Ceasar’s reign as immediately after the year Julius Ceasar died (44 BC).

Proof That the Fathers Believed Counted Years of Augustus’ Reign Immediately After Julius’. If you want to avoid a bunch of counting, I recommend that you go to the next subheading in which we will calculate Jesus’ age according to the years Irenaeus gives in his writings. For those of you who want the “proof” that Irenaeus was counting the 41st year of Augustus’ reign as 41 years after the death of Julius (around 3 BC), continue reading here:

While none of the church fathers had correct chronology, and the chronologies they offered differed among one another, it is worth saying that there are two fathers who actually mention when they thought Augustus’ reign began in relation to Julius Caesar’s reign. Both Clement of Alexandria and Isidore of Seville place Augustus’ reign immediately after Julius’.

Clement of Alexandria writes:

Caius Julius Cæsar, three years, four months, five days; after him Augustus reigned forty-six years, four months, one day. Then Tiberius, twenty-six years, six months, nineteen days. He was succeeded by Caius Cæsar, who reigned three years, ten months, eight days; and he by Claudius for thirteen years, eight months, twenty-eight days. Nero reigned thirteen years, eight months, twenty-eight days; Galba, seven months and six days; Otho, five months, one day; Vitellius, seven months, one day;Vespasian, eleven years, eleven months, twenty-two days; Titus, two years, two months; Domitian, fifteen years, eight months, five days ;Nerva, one year, four months, ten days; Trajan, nineteen years, seven months, ten days; Adrian, twenty years, ten months, twenty-eight days. Antoninus, twenty-two years, three months, and seven days; Marcus Aurelius Antoninus, nineteen years, eleven days; Commodus, twelve years, nine months, fourteen days.

From Julius Cæsar, therefore, to the death of Commodus, are two hundred and thirty-six years, six months….our Lord was born in the twenty-eighth year, when first the census was ordered to be taken in the reign of Augustus (Stromata Book 1, Chap 21).

In the whole block quote above, if you count all the years, one will see that the 236 years between Julius and Commodus allows for there to be gap of time between the reigns of the former and Augustus. Sure, Clement of Alexandria got his history wrong (he has Julius’ Caesar’s death at the wrong year), but that’s to be expected. Nonetheless, it gives us a clue about how the fathers counted the years of the emperor’s reigns.

Centuries later the wrong calculations surrounding the dates of Julius Caesar and Augustus Caesar’s reigns remained. Isidore of Seville in his Chronicon wrote:

64. Gaius Julius Caesar ruled for five years…The succeeding emperors were called “Caesars” after his name.

65. From the migration to Babylonia up to the nativity of our Lord Jesus Christ: 587 years. The fifth age came to an end in the year 5,155.

66. Octavian Augustus ruled for fifty-six years…the Lord Jesus Christ was born from a virgin in Bethlehem of Judah in the forty-second year of Octavian’s rule.

67. Tiberus, the son of the Augustus, ruled for twenty-two years…The Lord was crucified in the eighteenth year of his reign, 5,229 years having elapsed since the beginning of the world (Chronicon 64-67).

As we can see, if we take the year of Christ’s crucifixion (5229 after the creation of the Earth) and subtract it from the year in which Julius Caesar died (5155) we have 74 years. According to his count, Augustus ruled 56 years and Tiberius ruled 22 years, for a total of 78 years. Again, the math does not completely add up (unless we presume a co-regency overlapping between Augustus and Tiberius), but it is obvious that according to Isidore’s count Augustus reigned right after Julius.

Jesus’ Lifespan According to Irenaeus. According to Irenaeus’s chronology, Jesus lived to be somewhere between 44 to 57 years old (though for reasons discussed in our previous article, the very late 40s to very early 50s is the most likely). AH 3.21.3 places Christ’s birth at the 41st year of Augustus’ reign, so this would be around 3 BC. Ironically, this would be one year too late as the latest possible time Quirinius could have done a hypothetical census (which would have been 4 BC). To be fair to Irenaeus, a difference of a year is really marginal as we already know he is off for the year of Christ’s death and secular historians have a slight margin of error as we have imperfect records.

Now, as Mr. Ostrowski points out, in The Demonstration of Apostolic Teaching Irenaeus also wrote that Jesus died during the reign of Claudius. His first year as emperor was 41 AD and his last, 54 AD. So, the chronology Irenaeus gives actually corresponds with his view of “oral tradition” and interpretation of John 8:56-57 which he gives in AH 2.22.4-6.

In light of all this overwhelming evidence, it is time to admit the obvious. Irenaeus got things wrong. Plus, writing 150 years after Christ’s death and at least 85 years after the writing of the Gospel of John, the memories of non-essential* details, such as Christ’s age, have clearly been lost and misremembered. While Irenaeus boasted of having traditions relayed to him by elders who knew the Apostles plus the “self-evident” portrayal of Christ’s age in John 8, we can see that being a Bishop with Apostolic Succession did not assist him in straining through accurate traditions and properly interpreting the Scripture on this point.

*To Irenaeus, it probably was not a non-essential doctrine as it was to him a necessary condition that Christ achieved every age of mankind so that he can redeem men of all ages. This can be called the recapitulation theory of the atonement.

And so, if the institution of the church was unable to safeguard the inerrant interpretation of John 8 AND accurately relay extra-biblical tradition in the second century, on what basis may we reasonably believe that the church, institutionally, can do so at much later dates?

In the end, this should send us fleeing back to the Scriptures, the same source material that Irenaeus not only did not comprehend properly, but whose authority he was defending in Book III of Against Heresies. While we may lack an inerrant authority to interpret what that Apostles taught, at least we actually have writings of theirs where they tell us what they taught. And, that being the case, we do have an inerrant authority–the Scriptures.