Christianity V Judaism

Question

If Jesus was Jewish, then why do Christians believe in him? Wouldn’t Judaism & Christianity be the same thing in that way? (Sorry for stupid question)

Answer 1

Christians and Jews have the same foundation in the old testament. However, the old testament foretells the arrival of Messiah - the converted "Jews" believe that Jesus was that Messiah (leading to Christianity). This divergent in thought led to the initial two strand of Monotheism. Through the adoption of Neo-Platonic thought in the Greco-Roman world, Christianity developed a whole slew of other isms that diverge from Judaic thought, making the two religions in questions very different from one another.

Please note that this is a very, very simplified version.