I am an amateur compared to the great counter-missionaries out there, protecting the Jewish people from spiritual assimilation. For anyone interested in knowing why Jews correctly reject Jesus, here are some good essays.
An answer from Rabbi Shraga Simmons.
An answer from Rabbi Stuart Federow.
An answer from Ohr Somayach.
An answer from Rabbi Tovia Singer.
I would ask anyone who wishes to continue this debate to please read and digest these materials so as to provide a basis on which to speak. The only thing stopping you is fear.