"On the Apostolic Preaching" by St. Iranaeus of Lyon is amongst the definitive works of the Christian Church.
St. Iranaeus was the most influential and influential Christian writer of the Second Century (about 101 to 200 A.D.)
In his youth, Iranaeus had known Polycarp who had known the Apostles personally. The Apostles themselves had appointed Polycarp, who was later martyred in Rome about the late 150's, as Bishop in Smyrna.
Iranaeus had journeyed to Gaul (France) and the Lyon area, which was subjected to one of the most violent persecutions of early Christianity by Rome.
Iranaeus contended with this, and also with the growing threat to Christianity of the Heretical movements.
However, the writings of Iranaeus tell little of Iranaeus himself. Two works are known to exist.
(1) "AGAINST THE HERESIES" is a refutation of the heresies of the day, which much like the New Age works of our modern era, serve to pre-empt and subvert Christian doctrines. The commonality between ancient Gnosticism and New Age writings may come as a shock. Actually, they are one and the same.
For example, the reader will find that neither Gnosticism nor New Age writing possess a full doctrine of their own. Both operate in a "parasitic" manner. They adopt themselves to any and all relgious traditions, then invert, re-define or re-invent the theology of the tradition. Christianity is only one of the relgions which ancient Gnosticism subjected to this process. What one finds in both movements is the absence of a core doctrine, and rational corrollary doctrines derived from a single premise. Both are diffuse, scattered, and solipsistic (self-serving).
(2) "THE DEMONSTRATION OF THE APOSTOLIC PREACHING" is the work reviewed here. It is more commonly referred to as "On The Apostolic Preaching".