There is considerable doubt about the year of Irenaeus’ birth; estimates vary from 97 to 160. According to tradition, he learned the Christian faith in Ephesus at the feet of Polycarp, who in turn had known John the Evangelist. Some years before 177, probably while Irenaeus was still a teenager, he carried the tradition of Christianity to Lyons in southern France.

The year 177 brought hardship to the mission in Gaul. Persecution brokeout, and t…