Irenaeus lived approximately 130 a.d. to 202 a.d. The exact dates of his life are not known. Nor is the exact date he wrote his greatest work, a five-book series titled Against Heresies. His outline of heretical teachings is known to have been composed late in the second century. Until the discovery of the gnostic gospels at Nag Hammadi in 1945, it was from Against Heresies that most information about the gnostics was learned.
Irenaeus provides us a glimpse into the state of Christianity less than a century after the death of the apostles. What is revealed through that glimpse, is a bizarre bunch of conflicting views. Many of the teachings he condemned are so alien to today’s Christians that we would regard them as perverse aberrations. Yet they competed in the early Christian market place for converts, and claimed to be a true reflection of Christ’s teachings.
Christ foretold there would be “children of the wicked one” who would be planted among His “wheat” while they both grew together. (Matt. 13:24-30, 36-43.) The apostle Paul was astonished at how quickly the church at Galatia was corrupted with perverse teachings. (Gal. 1:6-7.) He predicted the entire falling away (apostasy) of the Christian church. (2 Thes. 2-3.)
While the apostles were alive and preaching, Christians divided themselves into contentious factions. Some followed one teacher, others another, and they emphasized their disagreements rather than their common beliefs. (1 Cor. 1:11-13.) “Ministers of Satan” were actively teaching inside the earliest bodies of Christians. (2 Cor. 11:13-15.) Paul lamented that “all of Asia” had fallen into error and rejected his teaching. (2 Tim. 1:15.) John warned of false spirits and false apostles who were spreading falsehoods that misrepresented Christ. (1 John 4:1-2.) By Nicaea, 324 a.d., the denial of Christ coming into the flesh was so widely accepted that a newly adopted and false teaching of the “Trinity” completed the overthrow of true doctrine regarding Christ who lived as a man in the flesh among us.
Even if falsehoods supplanted Christianity, John’s vision foretells that God’s patience will finally come to an end and the religions that worship devils, and gold, and silver and idols will be destroyed. (Rev. 9:20.)