1) Jesus didn't invent Christianity. He restored the true Jewish faith.
I used to think of Jesus as this guy who came along when the Roman Empire controlled Israel and said: "OK, everybody. You know all this Jewish stuff we do? The sacrifices and festivals and Shabbos services and everything? It's got to go! I have something totally new I want you to try. I call it 'Christianity' and you're gonna love it! And, even if you don't, I'm sure I can sell it to the goyim!"
But that's not what happened. What Jesus actually said was: "I have not come to destroy the Law (Torah), but to fulfill it." (Matthew 5:17). And when a Gentile woman asked Him for help, He at first declined, saying: "I am sent only unto the lost sheep of Israel." (Matthew 15:24). In fact, Jesus was born a Jew and He died a Jew.
His first followers were all Jewish, too. These Jewish men and women were steeped in Torah and the wisdom of the Jewish prophets. Remember, at this time the Temple still stood in Jerusalem. Jews went there to perform the sacrifices commanded by God. They lived in a country where observance of Jewish law was a fundamental part of everyday life. And when these Jews met Jesus, they immediately recognized Him as a great Jewish teacher (rabbi). Some even recognized Him as the Messiah promised in the Jewish scriptures.These devout Jews had no desire to start or join a new religion.All they wanted to do was to follow the God of Abraham, Isaac and Jacob. To them, becoming talmidim (students or "disciples") of Jesus was simply a way to draw closer to the God of Israel.
In fact, after Jesus died, his Jewish followers shared His message exclusively with other Jews: "They which were scattered abroad traveled as far as Phoenicia, Cyprus and Antioch, preaching the word to none but Jews only." (Acts 11:19). Imagine that! What we now call "Christianity" was once a club for Jews only! The Jews who believed in the Jewish Messiah didn't have any inclination to discuss the topic with the unclean Gentiles who lived around them. They only did so after God Himself commanded them to preach to the goyim about sin and salvation -- two concepts which, by the way, are totally Jewish and had no precedent at all in the Greco-Roman culture of the time.
Actually, the origin of the term "Christian" is unclear. It may have been coined by non-believing Gentiles to describe the largely Jewish followers of the Jewish Messiah. But there is no doubt that the first Jewish followers of Jesus saw themselves as Jews and nothing but Jews. They were simply responding to the wonderful visitation of the promised Messiah that had just occurred. They wanted to tell everyone about the arrival of God's Kingdom and His wonderful lovingkindess!
