Christianity began as a movement within Judaism. In this fascinating class, Rabbi Michael Skobac discusses the steps that may have led to its morphing into a totally non Jewish religion.
Here is a short introduction:
About 2,000 years ago, if you would have met someone who told you they believe that Jesus is the Messiah, you could have assumed that that person was Jewish. That was pretty much an assumption you could have safely made 2,000 years ago. Any person telling you that they are believer that Jesus is the Messiah, pretty good bet that that person was a Jew 2,000 years ago. The reason is that the movement initially the movement that was growing up around Jesus of Nazareth himself was an exclusively Jewish movement. Jesus instructed his followers in the book of Matthew chapter 10 when he told them to go round and spread his message, He told them “Go not unto the cities of the Gentiles or the Samaritans”. He tells them don’t go to non-Jews he said I have come only for the lost sheep of the house of Israel we see in the fifteenth chapter of Matthew that when a non-jewish woman comes to Jesus and his followers asking for help they send her away and she persists and says you have to help me and Jesus says to her, it is not proper to take the bread of the children and throw it to the dogs. That’s how we respond to this non-Jewish woman. So initially we know that the Jesus Movement was an exclusively Jewish movement and if you would have met anyone originally who said that they believed he was the Messiah you could rest assured that person was Jewish. However by the end of the second century, less than 200 years later, anyone claiming to be a Christian, anyone claiming to be a follower of Jesus, you could have safely assumed that person was not Jewish. So we see that at the very beginning of the Christian movement, a very radical shift takes place. In less than two hundred years the movement goes from about a hundred percent Jewish people to virtually 100 percent Gentile.