Nowhere. The struggle between the ancient Jews and the Egyptians was a political struggle, pitting one group of people (who called themselves God's chosen people) against another. It shows the Jewish people's victory over an enemy people. But the real spirit of Christianity is one that accepts people of all nations, as long as they follow the teachings of Jesus. Think about it: the story of the good samaritan explains that even people seen as enemies of the Jews can follow the way of Jesus through loving others. Thus, the Christians do not have an enemy people. Christianity is beyond borders.
Sunni Islam was the majority religion in Egypt in the 1800s. However, there were significant minorities of Coptic Christians, Rabbinic Jews, Karaite Jews, European Christians, and Baha'i.
I believe you are thinking about the Jews putting lambs blood on their door signifying they were Jewish during one of the ten plagues sent from God when the Jews were enslaved in Egypt.
No, Christians do not reject Jews. However, Jews reject Christians.
For the Jews its important, because that's when they got freed from being slaves under the Pharaoh in Egypt 3000 years ago for over 200.
Jews like Paul persecuted the christians.
Christians believe Jesus is the messiah, Jews don't.
Christians believe that the Messiah Has Come. Jews believe that He Has not.
Jews are not Christians. Christians believe that Jesus of Nazareth was the Messiah. Jews (and remember- Jesus was a Jew himself) believe that the Messiah has not yet come.
Islamic warriors had conquered Egypt by 656. Egypt has remained a Moslem country. ---- Since the Islamic Conquest of Egypt, Coptic Orthodox Christians and other Christians have continued to practice on the Nile, and in some areas have been dominant to this day. There have also been numbers of Jews.
They had the power to persecute Jews and Christians if they had wanted to
True Christians do not hate Jews. Nominal Christians may hate them because they are a different religion.
There is no prohibition on including Christians in a Hanukkah celebration, but most Jews will not go out of their way to invite Christians to join them.