A ecclesiastical historian specifically studies the history of Christianity, also known as ecclesiastical history. Church history studies the remarkable history of the growth of Christianity as a movement, in numbers and influence. Today the institution founded by Jesus Christ is the largest and most influential religion in the world, despite multiple efforts to stop its spread.
A methodical, scientific study of the growth and development of this movement must examine the claims that its Founder made and the evidence that bears out those claims. They include a declaration that the church would never die and that the Holy Spirit would continue to guide its growth and development in order to save mankind from its sin.
Within the historical method an ecclesiastical historian must study the tension between the free will of man and the possibility of supernatural intervention in any event. That God is an external causal agent acting in nature producing miracles cannot be analyzed by the scientific method. But when examination of historicity takes place through the historical method recognition of supernatural intervention is common for the ecclesiastical historian and should be seen as what sustained the church on the path that it has followed. 
|“||But, the apologist could continue, this is not the entire picture. In addition to the probabilities supplied by historical and other inductive arguments, there is also the ministry of the Holy Spirit, Who, as J. Oliver Buswell notes, provides "far more" than probabilities, as He convicts, regenerates, and energizes persons. The work of the Holy Spirit might come in the form of moving beyond the lack of "absolute certainty in terms of historical method," closing the gap and bringing "absolute certainty." Or it might be more a case of taking the historical facts and applying a personal faith decision. Thus, on the Christian understanding, historiography as a discipline can only yield some level of probability, since this is simply its limits. But believers need not rely on this basis alone. Of course, Bahnsen is certainly correct that the New Testament speaks of events such as Jesus' resurrection as having occurred, not as probably having occurred. But, then again, the New Testament also tells us that the Holy Spirit convicts believers of their salvation, thereby witnessing to the truth of the Gospel message. So there is certainly more to the story than history alone!||”|
- Main Article: History of Christianity
The first five centuries of Christianity are very important when establishing an exegesis of what the church means and the effects of its early development had on the ability to further establish and define itself. The church as a whole and individuals within during the first five centuries suffered physical, emotional and spiritual attacks the likes of which can be described as a holocaust against Christianity. The church withstands and thrives, later attaining great influence and even leadership of the very empire it was born under only 500 years later implies an incredible mechanism of change that was inherent in the original message by Christ that is being preached.
It can then be objectively seen within history of the lives of Christ's followers despite all efforts against them, the beliefs they held regarding His life, death and resurrection were indeed not only factual truths but life-changing beliefs for individuals and not mere figments of imagination or lies.
Notable Church Historians
- Kirsch, Johann Peter. "Ecclesiastical History." The Catholic Encyclopedia. Vol. 7. New York: Robert Appleton Company, 1910. Accessed September 16, 2008.
- History of Christianity by Wikipedia
-  Gary Habermas, "Greg Bahnsen, John Warwick Montgomery, and Evidential Apologetics. Global Journal of Classic Theology, 3:1 (2002): 240-242.
- The Beginnings of Christianity-With A View of the State of the Roman World At The Birth of Christ By George P. Fisher, D.D. Full Text Online.
- The Old Testament and the Archaeology of Palestine in The Old Testament and Modern Study, ed. H. H. Rowley (Oxford, 1951)
- The New Evidence That Demands A Verdict; How We Got the Bible, page 26 by Josh McDowell
- The 4th & 5th Centuries: The Church in Radical Change by Australian Catholic University
- The Bible and the Origins of Western Culture by Jeff Lukens