Early Christian Church fathers, such as John Chrysostom and Augustine, wrote extensively about the evil of the Jews and the responsibility of the Jewish people for the death of Jesus. Church Fathers affirmed that every Jew was fundamentally and repulsively un-Christian or anti-Christian and that Jews transmitted indelibly evil characteristics to their descendants.

Associating Jews with heresy, the second-century Christian apologist Justin Martyr argued that God had given Moses’ Law to the Jews to restrain the inherently sinful wickedness of the Jews. Augustine maintained that no Jew could ever escape the stigma of their ancestors’ denial and murder of Christ. He wrote that the evil of the Jews, “in their parents [in parentibus], led to death.” His mentor, Jerome, stated that all Jews were Judas and innately evil beings who betrayed the Lord for money. John Chrysostom, early church father and the archbishop of Constantinople, dubbed Jews deicides with no opportunity for “atonement, excuse, or defense.” Referencing Jeremiah 13:23, “Can a black man change his skin color or the leopard his spots?” in the seventh century, Isidore of Seville declared that the Jews’ evil character never changed. John of Damascus wrote that God granted the Jews the Sabbath due to their “absolute propensity for material things.”

The Jesuit periodical Civiltà Cattolica, backed and supervised by the Vatican, conducted an anti-Semitic crusade from the late nineteenth century until at least 1945. In 1880, Father Giuseppe Oreglia penned: "The Jews — eternal insolent children, obstinate, dirty, thieves, liars, ignoramuses, pests and the scourge of those near and far. Oh how wrong and deluded are those who think Judaism is just a religion, like Catholicism, Paganism, Protestantism, and not in fact a race, a people, and a nation! . . . For the Jews are not only Jews because of their religion . . . they are Jews also and especially because of their race." The following year, Oreglia added that driven by the devil, Jews could not become members of another nation or race, “they are born Jews and must remain Jews. Hatred for Christians they imbibed with their mother’s milk.” In 1904, French Catholic newspaper stated that “the Church of Satan is incarnated in the Jewish race.”

For two millennia, through sermons, theological writings, laws, art, and literature, Christian anti-Semitism has focused on the Jews’ persistent sins and crimes—their obstinate adherence to their perfidy, their avarice, their treachery, their servitude, and their murderous fury at Christ and Christians. On some occasions, Christian anti-Semitism resulted in the mass killing of Jews. Crusaders and other medieval Christians frequently massacred Jews, whom they deemed hopelessly unconvertible. These Christians, much like John Chrysostom and Martin Luther, regarded Jews as irredeemably Jewish and deserving of annihilation. The National Socialists harbored similar sentiments and, mutatis-mutandis, opted for the same resolution to the “Jewish Problem.”

During the early years of Christianity, numerous Church Fathers harbored unfavorable opinions of Jews and Judaism. The origins of Replacement Theology and the resulting anti-Semitism can be traced back to the early stages of Christianity. Many influential Church Fathers who played significant roles in shaping early Christianity promoted anti-Semitism:

Ignatius of Antioch (50-117 AD) taught that those who partake in the celebration of the Passover are partakers with those who killed Jesus.

Justin Martyr (100-106 AD) stated God’s covenant with Israel was no longer valid and that the church had replaced the Jews.

Irenaeus (130-202 AD) declared the Jews were disinherited from the grace of God.

Tertullian (155-230 AD) blamed the Jews for the death of Jesus and argued they had been rejected by God.

Origen (185-254 AD) was responsible for much anti-Semitism based on his assertion that the Jewish race was responsible for killing Jesus.

Eusebius (275-339 AD) taught that the blessings of Scripture were meant for the church, while the curses were meant for the Jews. He affirmed that the Church was the true Israel.

Hilary of Poitiers (291 – 371 AD) said, “Jews are a perverse people, accursed by God forever.”

Sylvester I (314-335), the pope at the time of Nicaea, ordered: "No priest shall… be friendly or sociable with Jews, nor should anyone take food of drink with the Jews, for if this was decreed by the holy apostles, it is incumbent upon the faithful to obey their command; and the synod shall excommunicate anyone who does not comply with this order."

Gregory, bishop of Nyssa (335–395 AD), said: "Jews are slayers of the Lord, murderers of the prophets, enemies and haters of God, adversaries of grace, enemies of their fathers’ faith, advocates of the devil, a brood of vipers, slanderers, scoffers, men of darkened minds, the leaven of Pharisees, a congregation of demons, sinners, wicked men, haters of goodness!"

Ambrose (340-397 AD) said: "The Jews are the most worthless of all men. They are lecherous, greedy, rapacious. They are perfidious murderers of Christ. They worship the Devil. Their religion is a sickness. The Jews are the odious assassins of Christ, and for killing God there is no expiation possible, no indulgence or pardon. Christians may never cease vengeance, and the Jew must live in servitude forever. God always hated the Jews. It is essential that all Christians hate them."

John Chrysostom (349-407 AD) preached a series of sermons against the Jews in which he stated: "The synagogue is worse than a brothel…it is the den of scoundrels and the repair of wild beasts…the temple of demons devoted to idolatrous cults…the refuge of brigands and debauchees, and the cavern of devils. It is a criminal assembly of Jews…a place of meeting for the assassins of Christ… a house worse than a drinking shop…a den of thieves, a house of ill fame, a dwelling of iniquity, the refuge of devils, a gulf and a abyss of perdition…I would say the same things about their souls… As for me, I hate the synagogue…I hate the Jews for the same reason." Chrysostom also stated that Jews could ever receive forgiveness. He affirmed it was a Christian duty to hate Jews and that Jews are Satan worshipers. Chrysostom is a canonized saint.

Jerome (347-420 AD) was the second-most voluminous writer after Augustine of Hippo in ancient Latin Christianity. Jerome described the Jews as: "Serpents wearing the image of Judas. Their psalms and prayers are the braying of donkeys… They are incapable of understanding Scripture."

St. Augustine of Hippo (354-430 AD) is admired for his many writings, primarily by Protestants, especially Calvinists and Lutherans, who consider him one of the theological fathers of pre-Protestant Reformation times. Augustine stated that the Jews deserved death but were destined to wander the earth humiliated as a witness to the victory of the church over the synagogue.

The Synod of Elvira (305 AD) was a council of bishops held in the city of Elvira (present-day Íllora) in the Roman province of Baetica. The counsel prohibited Christians from sharing a meal with a Jew, marrying a Jew, blessing a Jew, or observing the Sabbath. These decisions were part of a larger trend in the early Christian church of distancing itself from Judaism.