Differentiation refers to how educators accommodate the different capabilities of students as a means to cater for their learning needs.
Bacteria that have similar morphology can be diffrentiated by other tests such as; Gram staining, biochemical test, antigenic character, typing, antibiotic susceptibility test, and molecular techniques (such as PCR, DNA probe and nucleic acid hybridization)
Early on they didn't, in fact, early on most Christians were Jews. A first century Jew who followed Yehoshua (Jesus) as Messiah would not have stopped being a Jew anymore than Messiah himself stopped being a Jew. When he returns even, he returns as the "Lion of the tribe of Judah." (Jew is the modern short form of Jew) So a first century Jew would have seen himself as being a "good Jew" for recognizing the promised one and living for him. As time went on however, both sides began to build some animosity toward one another. More non-Jews were beginning to following Yehoshua, and many were bringing with them their uncleanliness, even some practices which stood outside of accepted practices as compared to scripture. By the 3rd century, non-Jewish followers of Yehoshua ceased going into the synagogies to hear scripture being read and laws began to be passed which further diffrentiated them from Jews. For example, in about 210 CE at the council of El Vira, a law was passed prohibiting the eating of Jewish foods. (clean/kosher) Many years later this was enforced by having believers in messiah forced to eat pork or die. Another hundred yars passes, and other laws are passed that divided Christians and Jews. Some of those laws included not allowing a Christian woman to marry a Jew, and another law changed the sabbath from the 7th day to the 1st. A millennium later, Christians came on horseback and killed Jews "in the name of Jesus." I have shown the dislike from mainly the Christian point of view but there was equal zeal by Jews to differentiate themselves from Christians.