How come the Jewish people generally reject the deity of Christ?
Most Jews reject the deity of the Messiah because they feel it is idolatry to worship a mere man as God, and that such a belief is a Gentile invention. But these are false assumptions that are flatly refuted by their own Jewish prophets, who they claim to revere. The Old Testament prophets predicted that the Messiah would indeed be divine (see Isaiah 9:6; Micah 5:2). You can show your Jewish friend these passages from his Jewish Bible. If he is honest and open-minded, he will admit that the Messiah is divine and that Jesus can be the only One who fulfills these prophecies.