Eusebius attempted to address several issues in The History of the Church: to record the lines of the successions of the holy apostles; to give record of important events in the history of the church; to give record of outstanding leaders and heroes of the Christian communities; to give the names and dates of those who have wandered as far as possible from the truth; to give record of the calamities that immediately came upon the whole Jewish nation because of their plots against our Christ; to give account of widespread persecution of the church and mention some who suffered martyrdom; and to address the nature of Christ. Eusebius gives an interesting account of early church history; however, the accuracy of his recording of historical events is questionable. Everett Ferguson, in his article "The Problem with Eusebius" states:
Many people know Eusebius of Caesarea as the Father of Church History. But as Robert M. Grant, a modern historian of the early church period, provocatively asked, "Did the Father of Church History write history?" Jewish historian Doron Mendels describes Eusebius's Church History as a "media revolution" and suggests that, because of his style of weaving short entries into a broader scheme, the author was "one of the fathers of the journalistic genre." Another writer concludes that Eusebius was "less a historian than a mediator of knowledge."
Eusebius used a variety of sources in his historical accounts; however, his sources were at time questionable. For example, in recording about the great historian Origen, Eusebius reports that Origen castrated himself to become a eunuch. However, Henry Chadwick, in his book The Early Church states, "Perhaps Eusebius was uncritically reporting malicious gossip retailed by Origen's enemies, of whom there were many." However, apparently Eusebius did not report this out of malice, Chadwick states that Eusebius "looked back at Origen as the supreme saint and highest intelligence in the catalogue of heroes in his history.
Eusebius also claims that Jesus wrote a letter to King Abgar of Edessa in Osrhoene. However, it is highly unlikely that Jesus wrote the letter. The King of Edessa during the time of Jesus' ministry was Abgar V Uchama. The fifth-century version of the legend, Doctrine of Addai, claims that Abgar also received a portrait of Jesus in addition to the letter. In addition, Eusebius claims that the woman with the issue of blood had a statue of Jesus erected in Caesarea Philippi. The statue was reported to be of a woman kneeling in front of a man who had one hand stretched out toward the woman. The male figure "was said to resemble the features of Jesus," and Eusebius claims, "the statue was still there in my own time, so that I saw it with my own eyes when I resided in the city."
However, the above-mentioned reports should not confuse the reader to assume that Eusebius only recorded gossip and fiction. Eusebius also reported many true events, and he gives extensive quotes from numerous sources. For example, Eusebius quotes from Irenaeus that the apostle John lived a long live into the reign of the Emperor Trajen. Eusebius reports events that may have actually happened, or are perhaps only very interesting legend. For example, John fleeing a bathhouse after discovering that the heretic Cerinthus was inside (HE 3.3.4).
Sometimes Eusebius' account is the only intact existing record remaining, or one of very few. For example, the Bishop of Hierapolis Papias authored five books, but only fragments have survived, and we know of his writings mainly from Irenaeus and Eusebius. Papias' account is important because his works help to support the evidence of who wrote some of the books of the New Testament. Papias records that Mark wrote the second Gospel. However, Eusebius tends to use Papias' account to support his own theories on books written by John. Eusebius infers from Papias' writings that there were two men by the name of John who contributed to the Cannon--John the apostle, and John the elder. Eusebius reports that 1 John is among the homologoumena, undisputed books, but that 2 John and 3 John were placed in the antilegomena, books disputed by some. He writes that all three letters are accepted by most people as Scripture regardless if they were written by the apostle John or by "another of the same name." Eusebius takes this information one step further by asserting that John the apostle did not write the book of Revelation. Eusebius also reports that Gaius rejected the book of Revelation perhaps as a way to support his own claims. Gaius actually claims that the heretic Cerinthus was the author of Revelation. However, Eusebius, later in his history, reports that John wrote all of the epistles attributed to him. Does not this weaken his two John account?
Eusebius spends a great deal of his history recording widespread persecution of Christians. William Tabbernee proposes that Eusebius had developed a theology of persecution:
Eusebius' political ideology was transformed dramatically by his experience of a decade of persecution. His related theology of persecution, however, is nuanced carefully. God remains both all-powerful and good. Persecution cannot occur unless God permits it. God only permits persecution for the good of the church. God does not initiate or unnecessarily prolong persecution. God merely withdraws the restraints normally in place to prevent persecution, thus allowing, for a time, the persecutors to do what they would have liked to have done anyway. Consequently, they and only they, are responsible for the atrocities committed during persecution and, hence, they thoroughly deserve the retribution meted out to them by divine justice.
Ultimately, Eusebius reports that God brings those who persecute the Christians to a bad end. For example, Eusebius reports that those outside the church suffered acts of God against them, "the seas were unnavigable, and wherever people sailed from they could not avoid being subjected to outrages of every sort . . . On them, too, fell the famine and pestilence that followed." The Emperor Galerius was also "pursued by a divinely ordained punishment, which began with his flesh and went on to his soul." Eusebius continues by describing an infection that started in Galerius' genitals and became ulcerated to his bowels to the degree that even the doctors who came near him were "unable to endure the overpowering and extraordinary stench."
In addition, Eusebius also saw the "calamities that immediately came upon the whole Jewish nation because of their plots against our Christ" as result of God's divine judgment.
Another example of Eusebius' assertion that calamity befell those outside the church is given with the above mentioned account of John and the heretic Cerinthus, who Eusebius refers to as the "enemy of truth." The legend of John fleeing from the bathhouse in Ephesus, when he discovered the heretic Cerinthus was there, seems to support Eusebius' thinking. John feared that God might intervene to destroy Cerinthus by causing the building to collapse, and John did not want to be inside the building in case that happened! This legend might have contributed to Eusebius's theology of persecution.
On the issue of heretics, Eusebius gives questionable accounts about Simon Magus, Simon the magician, who according to Acts 8: 9-24, was converted to Christianity under Phillip but was rebuked by Peter when he attempted to buy spiritual gifts. Eusebius claims that Simon Magus was "the prime author of every heresy." However, the Scriptures do not give voice to such claims. Eusebius reports that Justin claims that a statue was erected of the image of Simon in Rome, but a discovery in 1574 discovered that the statute was actually of Sabine Deity. In conclusion, in spite of his inaccuracies, Eusebius also confirms events that are documented elsewhere, or have been confirmed as actual events. For example, he reports that Constantine told him that before a battle he had seen a Christian symbol of the Greek letters pi and rho in the midday sun inscribed with the words, "By this conquer." However, it must be highlighted that Eusebius had a great admiration for Constantine--even to the point of giving Constantine Christ-like attributes. Constantine is idolized by Eusebius as the one who saves Christendom and the ultimately the Roman Empire because of his appointment by God. When reading the works of Eusebius the reader must use caution and take note that Eusebius himself held to the heretical doctrine of Arianism, which viewed the nature of Christ as subordinate to the Father. The reader is advised to view Eusebius' works with a critical eye.