Ambrose

Ambrose of Milan was a bishop, theologian, and Church Father of the fourth century. He warned young people against intermarriage with Jews, and in a letter to the emperor he defended the bishop involved in the destruction of the Callinicum synagogue near the Euphrates river.

Ambrose's letter
The following is from a letter from Ambrose to Emperor Theodosius I, defending the bishop involved in the destruction of a synagogue:

“... Shall, then, a place be made for the unbelief of the Jews out of the spoils of the church, and shall the patrimony, which by the favor of Christ has been gained for Christians, be transferred to the treasuries of unbelievers? We read that of old temples were built for idols of the plunder taken from Cimbri, and the spoils of other enemies. Shall the Jews write this inscription on the front of their synagogue: “The temple of impiety, erected from the plunder of Christians”?

... There is, then, no adequate cause for such a commotion, that the people should be so severely punished for the burning of a building, and much less since it is the burning of a synagogue, a home of unbelief, a house of impiety, a receptacle of folly, which God himself has condemned. For thus we read, where the Lord our God speaks by the mouth of the prophet Jeremiah: “And I will do to this house, which is called by my name, wherein ye trust, and to the place which I gave to you and to your fathers, as I have done to Shiloh, and I will cast you forth from my sight, as I cast forth your brethren, the whole seed of Ephraim. And do not thou pray for that people, and do not thou ask mercy for them, and do not come near me on their behalf, for I will not hear thee. Or seest thou not what they do in the cities of Judah?” God forbids intercession to be made for those.

... Will you give this triumph over the Church of God to the Jews? This trophy over Christ's people, this exultation, O Emperor, to the unbelievers? This rejoicing to the Synagogue, this sorrow to the Church? The people of the Jews will set this solemnity amongst their feast-days, and will doubtless number it amongst those on which they triumphed either over the Amorites, or the Canaanites, or were delivered from the hand of Pharaoh, King of Egypt, or of Nebuchadnezzar, King of Babylon. They will add this solemnity, in memory of their having triumphed over the people of Christ.

... And yet how great a thing it is, O Emperor, that you should not think it necessary to inquire or to punish in regard to a matter as to which up to this day no one has inquired, no one has ever inflicted punishment. It is a serious matter to endanger your salvation for the Jews. When Gideon had slain the sacred calf, the heathen said, The gods will themselves avenge the injury done to them. Who is to avenge the synagogue? Christ, whom they slew, whom they denied? Will God the Father avenge those who do not receive the Father, since they have not received the Son?

... And now, O Emperor, I beg you not to disdain to hear me who am in fear both for yourself and for myself, for it is the voice of a Saint which says: “Wherefore was I made to see the misery of my people?” [1 Maccabees 2:7] that I should commit an offense against God. I, indeed, have done what could be done consistently with honor to you, that you might rather listen to me in the palace, lest, if it were necessary, you should listen to me in the Church.”