Why is the Patristic Period important to Christianity?

Answer 1

The period said to be from the late close of the 1st Century AD (after the Apostle John dies on Patmos) to mid fifth century AD (some note 450 AD) was the time period of immense doctrinal diversity leading to an 'Age of Flux.' It is in this period that the Church 'Fathers' (some would call it the age of the early church children) had begun working out 'Church theology' - hampered by language with the Greek-speaking East and the Latin-speaking West.

Notable names include Justin Martyr who attempted to equate the Gospels to current Greek philosophical teachings; Irenaeus of Lyons who fought against the rise in Gnosticism considered 'heresies;' Clement of Alexandria explored the relationship between Christian thought and Greek philosophy; Tertullian supported the Latin theology produced significant and controversial apologetic writings quoted to this day; Origen presents the 'allegorical' interpretations of Scripture many mainstream churches are siding with today especially the Platonic ideas when describing Christology. There are many more names but perhaps Augustine of Hippo is best to end upon. He was involved with two major controversies: The Donatist and the Pelagian controversies - the former focused on the sacraments and the church while the latter focused on grace and sin. He also contributed to the 'trinity' doctrine.

For some then, this is the foundation of their church teachings while for others it is the foundation away from Christ's teachings.