The Christian attitude to Jews has tended to be episodic.
The Holocaust was never a religious affair, it was an attempted Racial extermination along with other Sub races defined by nazism.
Most of the Christian nations that attacked or threw out Jews in the middle ages did so because Christian rulers saw it as a cheap way to avoid their debts. The call of God Killer was an excuse and rallying cry to the masses.
In the early years of Christianity It was not Christianity, but the enmity between Israel and Rome that was the problem.
Jewish peoples have throughout the ages made themselves so easily identifiable, that they have been easily picked on by anyone looking for a scapegoat.
In the real world of day to day living, many of us have no Idea if our friends are Jews or not.
An event that well illustrates that, is that my Daughter and Son in law Invited a few fellow Doctor friends for a meal.
One of the dishes was a Quiche lorraine. It turned out two of their friends were Jews.
However, as no christian kitchen observes the necessary culinary rules anyway, It was a disaster waiting to happen.
For your historical edification:
From the earliest days of the Constantine and the Christian Roman Empire, Christians learned about the Jews in the context of how their god, Jesus, was killed by wicked Jews. In Christianity, Jews were always synonymous with Christ-killers – they were the Race of Deicides.
It begins with Book of Matthew 27:20 “And the whole people answering said: ‘His blood be upon us and our children.’”
The Book of John puts the proverbial nails in the crucifixion of the Jews when he relates the various evils that “the Jews” performed.
“… therefore did the Jews persecute Jesus because he did these things on the Sabbath.” (John 5:16)
“… The Jews then took up stones to stone him…” (John 10:31)
“We are not stoning you for any of these,” replied the Jews, “but for blasphemy, because you, a mere man, claim to be God.” (John 10:33)
“The Jews insisted, “We have a law, and according to that law he must die, because he claimed to be the Son of God.’” (John 19:7)
“’Here is your king,’ Pilate said to the Jews.
But they shouted, ‘Take him away! Take him away! Crucify him!’” (John 19:14,15)
Apparently the early Christian theologians believed that these passages specifically meant that the Jews first rejected, and then killed Jesus. And, that the Jews were therefore cursed.
Origen, one of the most distinguished writers of the early Christian Church, wrote: “The Jews nailed Christ to the Cross.”
Cyprian, bishop of Carthage, took time to detail the crimes of the Jews in his “Three Books of Testimonies Against the Jews.”
Augustine argued that Jews should be left alive and suffering as “a perpetual reminder of their murder of Christ.”
Gregory of Nyssa named the Jews “Slayers of the Lord, murderers of the prophets, adversaries of G-d, haters of G-d … advocates of the devil, brood of vipers, slanderers… assemblies of demon… and haters of righteousness.”
John Chrysostom (347-407), flatly stated (contradicting Peter who claimed the Jews acted without knowledge) “the Jews erred, not ignorantly, but with full knowledge.”
Chrysostom’s virulent hatred of the Jews, as the Archbishop of Constantinople, along with these other Church Fathers, forever influenced the theology that became Law under the Eastern Orthodox Empire, and he, like the rest of these early Church Fathers, became a “saint.”
Among his many sermons castigating, excoriating, and cursing the Jews, he called them “the assassins of Christ” and named their synagogues “the refuge of devils and abyss of perdition.”
Ultimately, the “Holy Roman Emperor,” Constantine, began what became a perpetual theological condemnation of Jews and Judaism in his:
Laws of Constantinus Regarding the Jews
(It is worthwhile to state the first Law in full as this enjoyed the full Ecclesiastical weight of the Holy Roman Church and was not merely a “civil law,” but Christian doctrine.)
I. Laws of Constantine the Great, October 18, 315: Concerning Jews, Heaven-Worshippers, And Samaritans We wish to make it known to the Jews and their elders and their patriarchs that if, after the enactment of this law, any one of them dares to attack with stones or some other manifestation of anger another who has fled their dangerous sect and attached himself to the worship of God [Christianity], he must speedily be given to the flames and burn together with all his accomplices. Moreover, if any one of the population should join their abominable sect and attend their meetings, he will bear with them the deserved penalties.
The Emperors and therefore Patriarchs of the Holy Roman Christian Church, Theodosius II and
Justinian, continued making specific Laws restricting and condemning Jews and Judaism, as did nearly every Holy Roman Emperor and later, Popes, that followed in the footsteps of these Christian “saints” who urged that Jews be scourged and hated for killing their god.
This theology was passed on to all of Christendom well into the 20th Century.
All Christians “knew” that Jews were “cursed” by G-d and it was the theological duty of greater Christendom to see that they suffered.
And, greater Christendom did exactly that.
The first recorded mob violence that I know of was in 388 CE when Christians burnt down a synagogue in Syria.
From the 5th Century onward - Jews were regularly killed; forced to convert; their synagogues and homes burned and looted; forced to pay a “dhimmi tax” to Christians in order to both practice Judaism and/or simply not be killed; prohibited from certain occupations; not allowed to marry Christians; their books burned; expelled from various Christian kingdoms; and simply persecuted unendingly by Christians for the crime of being Jewish.
At any time, in any country, for any reason, Jews could be and were ruthlessly sought out for torture and death.
Millions of Jews died at the hands of Christians over the last 1500 years for the supposed theological crime of being Christ Killers.
With the conclusion of the Holocaust in the 20th Century, most of Christianity officially changed their theology and no longer claimed that the Jews killed their god.
Now, the Islamist Loony Tunes have picked up on Christian Hate-the-Jews theology with their own passages from their scriptures and are carrying the torch of persecuting Jews and defaming Judaism.
This was not a natural development in Islam, but is descended directly from the hatreds of Christianity; Naziism and Stalinism.
Before the 20th Century, the pertinent “pig” and “monkey” passages, which are not directly from the Koran regarding Jews but, are interpretations of Koranic passages, were an embarrassment to Muslims who preferred to gloss over these issues along with the famous slaughter by Mohammad of the Jews.
With the rise of both Israel and the successful Jihad of the Wahhabist Saudi Arabians, these obscure anti-Jewish passages became key quotes in Islamist and Arabist hatreds.
Those who wish to differentiate between Christianity and Judaism will surely point out that Jesus never told Christians to kill the Jews and Mohammad did, indeed, tells his followers to kill the Jews.
Despite these apparent contradictions, Jews found refuge from mass murder and persecution by Christians in Muslim and Arab lands for over 1,000 years.
The persecutions and killing of Jews by Muslims during that time was not Jew specific. Various Muslim rulers killed Muslims; Jews; Christians; and others with impunity as the nations were at war or theological crises came about.
It is only since the rise of Islamic fascist death cultism that the shoe is now on the other foot.
Christians, particularly American Christians, are today the best friends Jews could possibly have.
Muslims are not.
Nonetheless, for over a thousand years, all of Christianity firmly believed that their god had condemned and cursed the Jews as Christ Killers and Deicides. It is that heritage which influenced all of Christianity which in turn influenced all of the "Western World," which has today influenced the entire planet.
And, regarding the Jewish State Israel - the secular and Islamist world has simply transmuted this deep cultural theology of Jew hatred into the amorphous hatred of Israel as somehow MORE "evil" than any other country in the world.
The notion is absurd when one considers that the majority of countries and cultures on planet Earth treat their subjects and their enemies with infinitely more savage barbarism than the manner in which Israel treats its subjects; its citizens; and its enemies.