By the late second century, Christians already faced a problem familiar today:
Different groups claimed to possess the authentic teaching of Jesus.
How did Irenaeus answer?
Not Secret Christianity
Irenaeus opposed Gnostic teachers who claimed special knowledge.
He argued that authentic Apostolic teaching was public and traceable.
He appealed to:
- Scripture;
- Apostolic Tradition;
- churches connected to the Apostles;
- succession of Church leaders.
Elsewhere he tells Christians to obey presbyters who possess succession from the Apostles.
Primary Sources
Against Heresies, Book III:
https://www.newadvent.org/fathers/0103303.htm
Succession discussion:
https://www.newadvent.org/fathers/0103426.htm
Rome Appears
Irenaeus also points to the Church at Rome, associates it with Peter and Paul, and gives a succession of Roman bishops.
The precise implications of his famous Rome passage are debated.
That debate should be studied.
But Rome's importance in his argument cannot simply be erased.
The Authority Question Is Already Here
Around AD 180, Christians are not merely asking:
"Which interpretation of a verse do I personally prefer?"
They are asking:
Who preserves the Apostolic faith?
That question becomes central to the Catholic-Protestant debate many centuries later.