Church Fathers are individuals of great importance to Christianity because of their leadership, and particularly their writings that highlight characteristics of early Christianity from which immense insight can be found. Insight into both the early history and theological doctrines from early Apostolic Fathers allow coherence for modern Christianity. The term Apostolic Fathers is very important to determine and symbolize chronologically the authority of orthodox Christianity.
Other more general labels have church fathers grouped as ante-Nicene and post-Nicene, or the time after Christ but before the Council of Nicea and after the Nicene Council. These broader terms account for broader spans of time respectively in which allows overlapping of what should remain separate. It is not wrong but does not capture the consistency and clarity of doctrine authority that the Apostolic and post-Apostolic lines do. The term early church fathers does not see any division until post Nicene Council and thus is used to describe all church fathers from the time of Christ up until the Council of Nicea or the writings of Eusebius of Caesarea, around AD 325. The term early church fathers is also preferred as it captures both the Apostolic and post-Apostolic lines within its chronological framework.
The New Testament was written in full prior to 100 AD only surviving in fragments of copies into the second century (100-200 AD). Christianity continued to grow however, exponentially, despite the threat it was under. Demand for Scripture was met as time went on, allowing greater numbers and considerably more complete forms of the NT to be present in more and more churches. New Testament growth can be seen to progress in parallel with the Apostolic fathers lives. As they grew older in age so did NT authority and availability within the Christian church. As authority goes from Christ to his Apostles and from the Apostles to their pupils, the Apostolic fathers, it goes onto the post-Apostolic fathers and so on. The more removed the teachings of doctrine become from the ultimate authority of Christ however the less authority they maintain for modern Christianity. The Apostolic fathers are considered contemporaries of the Apostles of Jesus Christ. They are Clement and Bishop of Rome, Igantius of Antioch and Polycarp of Smyrna, their non canonical early Christian writings date from about 96 to 156 AD. The Apostolic fathers authority is highlighted in their methods based on faithful oral tradition and essentially parroting past teachings, rather than performing systematic theology. The Apostolic fathers and their writings are vital in determining what leaders of the early Christian church believed and taught. Apostolic fathers were present during the writing of the New Testament but they were not included as biblical canon.
Clement of Rome
Pupil of John the Apostle, Clement of Rome was also a Bishop of Rome and considered to be the first apostolic father. He wrote a letter to the Corinthians in about 96 AD, although others do place its composition around 70 AD. The only real firmly established date is a range from 75 to 110 AD for the composition of the letter to the Corinth church by Clement of Rome.
Pupil of the Apostle John (who died 10-15 years earlier) Ignatius was Bishop of Antioch and lived from 35 or 50 to about 98 or 117 AD. He wrote seven letters in about 107 AD while en route to be martyred by beasts. He articulated the early church belief that Christ was God and a bodily resurrection. Ignatius of Antioch was also the first to declare that catholic church merely meant the universal Christian church.
Pupil of the Apostle John, Polycarp of Smyrna was born 69 AD and died approximately 156 AD.
Some post-Apostolic fathers were contemporaries of the Apostolic fathers whom were pupils of the apostles of Christ. The Apostolic and post-Apostolic fathers were prominent apologists that defended Christianity against critics. The history of Christianity and Christian thought is derived through these theologians, apologists and historians. The direct line of authority from Christ, starting around 30 AD, begins to deteriorate in a matter of four to five generations or about 200 years after His death and resurrection. After the completion of the New Testament in the first century AD, external critics of the second century emerge such as Celsus. Celsus observed Christianity and harshly criticize it based on it standing in society. During the third century AD there is then introduced heresy and serious internal challenges within the Christian church.
Authority of the Apostolic line can be determined to deteriorate because of the rising New Testament authority with one view, yet another view maintained by the Roman Catholic church is that authority has continued into the present day through a human line of post-Apostolic line. This teaching is seen as heretical to critics who contend that the line of succession from Peter to the current Pope gives infallible authority to man far removed from original doctrine and worship of early Christianity. When the Apostolic fathers died or were martyred for their faith in Christ so did an era of Apostolic succession authority. As time progressed however church fathers and others as time went on, far removed from Apostolic authority tend to entertain controversial notions and at times attempt to amend or deviate from established doctrine. The void left after the death of authoritative teachers and the birth of internal doctrinal differences within the church was filled by New Testament literature. The Apostolic fathers writings and teachings seen with the New Testament as overarching take on a supplemental and complimentary role while the post-Apostolic fathers are subordinate to not only the NT but also the Apostolic fathers.
- Main article: Justin Martyr
He was born around 114 AD in Flavia Neapolis, a city of Samaria and was most likely well educated having traveled extensively. He later became a disciple of Socrates and Plato through which he developed his philosophies on life and soon gravitated towards Christ.
The writings of Justin Martyr are among the most important that we have from the second century AD. His writings are not the first written on the subjects he covers, what are called his Apologies, but are the earliest extant.
One of his most important writings entitled the Dialogue with Trypho, is the first detailed reasoning for Christ as the Messiah of the Old Testament. That also essentially became the first attempt to reason with the Jews in regard to their views as compared to that of Christianity regarding Christ's prophetic implications.
- Main article: Irenaeus
Thought to be Greek Irenaeus was born around 130 AD in what was called Smyrna in the Bible and Izmir in modern day western Turkey. His interest in Christianity was sparked by hearing Polycarp preach who was taught by the Apostle John, who was an eyewitness to Christs life, death and resurrection. Because of the connection to one who witnessed and was a disciple of Jesus, Irenaeus is an important figure within ecclesiastical history as his writings are very close to primary eyewitness sources.
- Main article: Tertullian
Tertullian was born in 160 AD in Carthage which was in modern day Tunisia. He has left 31 extant treatises dating from around 190-220 AD, and converted from Paganism to Christianity around 197 AD. He is known as the first Christian to write in Latin.
Tertullian grew angry when he witnessed compromise in the church, namely unwillingness to be martyred, and willingness to forgive more serious public sins. For these reasons he aligned himself with the Montanist movement and dealt with such subjects in his writings.
- Main Article: Origen
Origen was a Christian scholar and theologian and one of the most distinguished of the Fathers of the early Christian Church. He was born in 185 AD, probably in Alexandria, Egypt and died in Caesarea in 254 AD. Origen attempted to defend Christianity against the attacks of both Judaism and Gnosticism by marrying Neoplatonism and Christianity. He reached the same conclusions as the majority early church writers in his belief that creation was ex nihilo. Origen cites Hermas’ Shepherd (Mandate 1 [26:1]) as support for this belief: “First of all, believe that God is one, who created all things and set them in order, and made out of what did not exist everything that is, and who contains all things, but is himself alone uncontained.” 
- Main article: Eusebius of Caesarea
Eusebius of Caesarea (ca. 260-ca. 340 AD), the "Father of Church History," had an aptitude for historical research superior to that of all other Church authorities who preceded him or were contemporary with him. He was curator of the Library of Caesarea (after Origen and Pamphilus) and while there he wrote his most famous work, the Ecclesiastical History. He is best known for classifying all the known works of or inspired by the Apostles and thus laying the foundation for the development of the New Testament canon.
- Apostolic Fathers
- Apostolic Fathers: Volume I. I Clement. II Clement. Ignatius. Polycarp. Didache. Barnabas (Loeb Classical Library No. 24) by Kirsopp Lake. pg 3
- Papal Line of Succession St. James Catholic Church
- History of Christian Thought - Part 5 By Dr. Phil Fernandes. Posted: Wed, 03 Dec 2008
- Pearse, Roger. "The 'Noddy' Guide to Tertullian." The Tertullian Project, September 27, 2008. Accessed October 4, 2008.
- Joseph W. Trigg, Origen. London: SCM Press, 1983. p.120; J.F. Bethune-Baker, An Introduction To The Early History Of Christian Doctrine. London: Methuen & Co., 1903. pp.24-25.
- On First Principles 1.2-3 (ANF, Vol. 4, pp.245-256); John 1.17; 32.16.
- Davis, Glenn. "Entry for Eusebius." The Development of the Canon of the New Testament, 2008. Accessed October 4, 2008.
- The Church Fathers on the Genesis Flood by Paul Garner. Published: 28 February 2012
- Early Church Fathers In this electronic edition of the Early Church Fathers series, the volumes have been carefully proofed and converted to ThML by CCEL staff and volunteers.