“As long as a city is encircled with walls all around,” wrote John Chrysostom, “it mocks its besiegers and remains in perfect safety. But once a breach is made in the wall, no larger than a gate, the circuit is no more use to it, though all the rest stands safe.”

It is the same, he says, in the church: “As long as the nimble wits and the wisdom of the shepherd encompass it like a wall all around, all the enemy’s devices end in his own shame and ridicule, and the inhabitants remain unharmed; but when someone manages to break down a part of this defense, even though he fails to destroy it all, from that moment practically the whole city is ruined through that one part.”

As a “shepherd,” Chrysostom tried to defend the faithful with faithful preaching. He was especially concerned about three questions that troubled the church at the end of the fourth century.

Is Jesus God?

Chrysostom began preaching just after Arianism, a teaching that denied the full deity of Christ, had been officially condemned (by the Second Ecumenical Council in 381 and by Emperor Theodosius). After fifty years of ascendancy, the political power of Arianism was gone, but it remained influential at Antioch and Constantinople.

Chrysostom argued that such heresy is produced by following human reasoning rather than the true sense of Scripture. It may arise from not reading the Bible, or from something more sinister: “The desire to rule,” he once said, “is the mother of heresies.”

In his attacks on Arianism, Chrysostom cared as much about the Arians’ moral defects—their vanity and self-seeking—as about their misunderstanding: “They are like some labyrinth or puzzles which have no end … and have their very origin in vanity.… Ignorant of heavenly things, they involve themselves in the dust cloud of countless reasonings.”

Chrysostom defended the right use of reason. But he believed Greek culture, which reveled in rationality, produced speculation about Christian realities that led to doctrinal errors such as Arianism:

“For nothing causes such dizziness as human reasoning, all whose words are of earth and which cannot endure to be enlightened from above. Earthly reasonings are full of mud, and therefore we need streams from heaven, that when the mud has settled, the clearer portion may rise and mingle with the heavenly lessons.”

Chrysostom, by the way, distinguished between heretics, who misunderstand doctrine, and false prophets, who are morally corrupt and can do no good: “Do not make an issue of the various heretics of different hue and color. They all proclaim Christ even if they lack something in orthodoxy. They all reverence the One who was crucified under Pontius Pilate in Palestine.”

To refute the Arian arguments, Chrysostom interpreted biblical passages to show the equality of the Son with the Father. The Scriptures that seem to support the Arian position (those that show Jesus as human), he attributed to “the condescension of the Incarnation,” that is, the accommodation of Christ to his human nature.

The very fact of the Incarnation, argued Chrysostom, proves both the humanity and divinity of Christ: if he were not God, he would not have humbled himself but would have clung to his higher status!

Do Jews Bring Luck?

In Chrysostom’s time, Judaism was the creed of an existing nation, venerable for its antiquity even when exiled from its homeland. A significant Jewish community existed in Antioch, and the holiness of the synagogue in which the one God was worshiped and where the sacred books were preserved made a deep impression on Christians.

But their attraction to Judaism was superstitious more than religious. For example, some Christian women wore Jewish amulets, and many Christians took oaths (for legal purposes) in the synagogue and sought out Jewish physicians for medical cures.

In a series of sermons delivered at Antioch in 386 and 387, Chrysostom attempted to diminish the prestige of Judaism in the eyes of Christians. He argued that Christians should not practice the ceremonies of Judaism, for the Old Testament points beyond itself to a higher form of religion through a system of types and foreshadowings. Furthermore, the Old Testament dispensation, though totally appropriate for its period, became inadequate and untenable when the new epoch dawned— just as the light of the moon becomes superfluous when the sun rises.

The general principle is this: an action commanded by God must be performed at the right time; at the wrong time, it can be harmful or foolish. To Chrysostom, the institutions of Judaism were no longer timely and thus no longer pleased God.

Chrysostom’s sermons by today’s standards sound vehement and anti-Semitic. Some scholars suggest they led to later confrontations between Jews and Christians. But in contexts other than Christian Judaizing, Chrysostom spoke approvingly of the Jews. As bishop of Constantinople, for example, he praised them for scrupulously obeying their law, unlike lazy Christians who were unwilling to expend any effort on practicing their religion. He also commented on the respect in which the rabbi was held by his congregation, in contrast to his own treatment, as patriarch, by fellow Christians.

Is Paganism True?

Despite the toleration and gradual rise of Christianity in the fourth century, many pagans refused to convert. There were diehards and apostates, like Emperor Julian (a.d. 361–363), who anticipated the collapse of Christianity and the re-establishment of paganism: “The foolishness of the Galileans (i.e., Christians) has all but destroyed society,” he once wrote, “were it not for the favor of the gods, which preserves us all.”

Many pagans were also skeptical of Christianity when they saw the prevalence of nominal Christianity among the masses, worldliness among upper-class Christians, and inordinate ambition among the clergy. This Chrysostom recognized: “They see our lives open to reproach, our souls worldly. We admire wealth equally with them, and even more. We have the same horror of death, the same dread of poverty, the same impatience of disease; we are equally fond of glory and of rule.… How then can they believe?”

Chrysostom countered pagan criticism of Christianity with his own criticism of Greek culture and religion. He had studied with pagan teachers, learning the Greek classics of poetry and philosophy, but he had found them lacking.

He attacked popular polytheistic paganism. A local pagan prophetess, he said, prophesied through the inspiration of evil spirits, and Apollo himself was a demon. He contrasted the Olympic games (dedicated to the Devil), with Christ’s contest, in which the rules are totally different: the person smitten rather than the person smiting is crowned!

He also questioned the very basis of pagan culture. Pagan culture, he said, was based upon vanity and materialism, the ideal of beauty as opposed to the ideal of service. Pagans preferred eloquence to virtue and truth.

Making use of the apostle Peter as a symbol of the church, he once said, “Where now is Greece, with her big pretensions? Where the name of Athens? Where the ravings of the philosophers? He of Galilee, he of Bethsaida, he the uncouth rustic has overcome them all.”

The success of a humble, rustic Christianity was to Chrysostom a key proof of its truth: “I once heard a Christian disputing in a ridiculous manner with a Greek, and both parties in their mutual fray ruining themselves.… The dispute being about Paul and Plato, the Greek endeavored to show that Paul was unlearned and ignorant, but the Christian, from simplicity, was anxious to prove that Paul was more eloquent than Plato.”

With this line of reasoning, Chrysostom said, victory would go to the Greek even if the Christian won the debate: “For if Paul was a more considerable person than Plato, many probably would object that it was not by grace but by excellency of speech that he prevailed.”

Instead, Chrysostom argued, “If Paul was uneducated and yet overcame Plato, the victory … was brilliant.” The triumph of the gospel could only be seen as a grace of God, not a human or political triumph.

Bringing the Dead to Life

Chrysostom believed that arguments alone could not overcome the dangerous heresies of his day. Christian deeds were essential.

“Let us show forth then a new kind of life. Let us make earth, heaven; let us hereby show the Greeks of how great blessings they are deprived. For when they behold in us good conversation, they will look upon the very face of the kingdom of Heaven.… Thus they too will be reformed.… For not even a dead man raised so powerfully attracts the Greek as a person practicing self-denial.”

John preached against, argued over, and even mocked superstition, paganism, and heresy, but he did so with pastoral compassion: “Our song leads us in the battle against the heretics, not to throw to the ground that which is standing upright, but to raise that which is lying prostrate. That is our kind of battle. It does not kill the living, but brings the dead to life.”

Margaret Schatkin is associate professor of theology at Boston College and author of “John Chrysostom as Apologist” (Patriarchal Institute for Patristic Studies, 1987).