Today the Church honors Irenaeus, a second century saint. For Irenaeus it was most important to us that we hold on to the Church’s beliefs that came straight from Christ and the Apostles, not mixing in any false Christian-like practices.
Irenaeus had spent his boyhood listening to the stories of an old man named Polycarp, and Polycarp had spent his boyhood listening to John the Apostle telling stories about Jesus.
In the year 130 there was an active trade between Irenaeus’s home place of Smyrna, and the French city of Lyons. On a business trip to Lyons, Irenaeus used wisdom he had from Polycarp to clean up Church problems. It ended with their asking him to be their bishop.
Next, his childhood link through Polycarp back to St. John and Jesus came to be valued in Rome. Being called there, he cleared out many false religious notions that people were spreading. In that second century something like Astrology became popular. Where as Astrology finds messages for us from the planets and the stars, the fad then had people believing that each heavenly body had each own angel that moved it around. They developed number games for getting code messages from those angels.
The Greek word for “I know” is gnosco. Those people were such know-it-alls that they came to be called Gnostics.
Irenaeus spent months with each group of Gnostics, leaving us a two hundred page summering of what each group was saying.