Dear Brothers and Sisters:

In the history of ancient Christianity, there is a fundamental distinction between the first three centuries and those following the Council of Nicaea, the first ecumenical council in the year 325. As a “hinge” between the two periods is the so-called change of Constantine and the peace for the Church, as well as the figure of Eusebius, bishop of Caesarea in Palestine.

He was the most qualified exponent of the Christian culture of his time in the most varied of contexts: from theology to exegesis, from history to scholarship. Eusebius is known, above all, as the first historian of Christianity, but also as the greatest philologist of the ancient Church.

In Caesarea, where he was probably born around the year 260, Origen had earlier taken refuge, fleeing from Alexandria. There, Origen had founded a school and a huge library. It is precisely from those books that the young Eusebius would receive his formation some decades later. In the year 325, as bishop of Caesarea, he played a main role in the Council of Nicaea. He authored the Creed and the affirmation of the full divinity of the Son of God, defined by Eusebius as “one in substance with the Father” (homooúsios tõ Patrí). It is practically the same Creed we recite at Mass every Sunday.

A sincere admirer of Constantine, who had given peace to the Church, Eusebius felt esteem and deference toward him. He praised the emperor, not only in his works, but also in his official addresses, delivered on both the 20th and 30th anniversary of the emperor’s coming to the throne, as well as after his death in the year 337. Two or three years later, Eusebius would also die.

A tireless academic, Eusebius, in his numerous works, sought to reflect upon and take stock of the three centuries of Christianity, three centuries lived under persecution. He consulted, for the most part, the original Christian and pagan sources that had been preserved in the great library of Caesarea. Thus, despite the objective merit of his apologetic, exegetical and doctrinal work, Eusebius’ long-lasting fame is linked, first and foremost, to his 10-volume “Ecclesiastical History.” He was the first to write a history of the Church, and to this day his work is still foundational, mainly due to the sources Eusebius puts forever at our disposal. His “History” preserved from sure oblivion numerous events, people and literary works of the ancient Church. His work is therefore a primary source for knowing the first centuries of Christianity.

We may ask how he structured this work and what his intentions were in writing these volumes. At the beginning of the first book, the historian presents the arguments he is going to address in his work: “It is my intention to record the succession of the holy apostles from Our Savior to our day: how many and how important were the events that took place according to the history of the Church, and who were distinguished in their governance and direction of the most notable communities, including those who, in each generation, were ambassadors of the Word of God, either by means of the written word or without it, and those who, motivated by the desire for innovation to the point of error, have become promoters of what they falsely call knowledge, thus devouring the flock of Christ like fierce wolves … also the number, the customs and duration of the pagans that fought against the divine word, and the greatness of those who, because of this, endured the test of blood and torture; noting also the martyrs of our time and the merciful and favorable help which Our Savior offers everyone” (1,1,1-2).

In this manner, Eusebius covers various topics: apostolic succession, as the structure of the Church, the spreading of the Message, errors, persecutions by pagans, and the great testimonies which constitute the shining light of this “History.” Amid it all, shine the mercy and goodness of the Savior.

Thus Eusebius inaugurates ecclesiastical historiography. His narrative covers up to the year 324 when Constantine, after the defeat of Licinius, was proclaimed as the only Roman emperor. This is the year that preceded the great Council of Nicaea, which later offered the “summa” of what the Church had learned over those 300 years — doctrinally, morally and even legally.

The quote we have just mentioned from the first volume of “Ecclesiastical History” contains a repetition that is certainly intentional. In just a few sentences, he repeats the Christological title “Savior” and makes explicit reference to “his mercy” and “his benevolence.” Thus we can understand the fundamental perspective of Eusebius’ historiography: It is a Christocentric history, in which the mystery of God’s love for men is progressively revealed. With genuine surprise, Eusebius recognizes: “Of all men of his time and of all men who have ever existed on the earth, only he is proclaimed and confessed as Christ (that is, as “Messiah” and “Savior of the World”), and all give testimony to him with this name, both Greeks and barbarians call him this. Besides, even today, across the land, he is honored as king by his followers, contemplated as superior to any prophet, and is glorified as the true and only high priest of God; and, above all, He is adored as God because he is the pre-existing Logos, who existed before all times, and has received from the Father the honor of being an object of veneration. And what is most significant about this is that we who are consecrated to Him do not honor him with our voices alone or the sound of our words, but with a complete readiness of soul, to the point of preferring martyrdom for his cause more than our own lives” (1,3,19-20).

In this manner, we see first of all another characteristic that will be a constant in ancient ecclesiastical historiography: the “moral intent” that gives direction to the narrative. Historical analysis is never an end in itself; it seeks not only to get to know the past, but it firmly points toward conversion and to an authentic witness of Christian life on the part of the faithful. It is a guide for us today.

Eusebius, then, poses poignant questions to the faithful of every age regarding the manner in which they face the changing circumstances of history and, in particular, of the Church. He questions us too: What is our attitude toward the vicissitudes faced by the Church? Is it the attitude of someone who is interested out of mere curiosity, looking for sensationalism and scandal at all costs? Or is it rather the loving attitude, open to mystery, of one who because of faith knows that he can discern in the history of the Church the signs of God’s love and the great work of salvation he has accomplished?

If this is our attitude, we should feel invited to offer a more coherent and generous response, a more Christian testimony of life that will leave an imprint of God’s love for future generations as well.

“There is a mystery,” tirelessly repeats the eminent scholar of the Church Fathers, Cardinal Jean Daniélou: “There is a content hidden in history. … The mystery is that of the works of God that form, in time, the authentic reality that lies hidden beneath appearances. … But this history that God accomplishes through man, he doesn’t accomplish without Himself. To contemplate the ‘great works’ of God would mean to only see one aspect of things. Before the things, there is the answer” (“Saggio sul Misterio della Storia” [Essay on the Mystery of History], Brescia 1963, p. 1982).

Many centuries later, Eusebius of Caesarea still today issues an invitation to believers. He invites us to be awed by and to contemplate the great work of salvation that God has accomplished in history. And with the same vigor, he invites us to a conversion of life. In fact, before a God who has loved us so much, we cannot remain unaffected. The very demand of love is that all of life be oriented toward the imitation of the Beloved. Let us do all within our power to leave in our lives a clear imprint of God’s love.