What do Christianity and Judaism have in common? Most Christians relate to Judaism more than to Islam, Hinduism, or Buddhism, or any other religion. So, my question is, what do Christianity and Judaism have in common so as to make them so related to one another? Thanks.
Jesus Christ is Jewish. Therefore we are connected to the Jewish faith because it is our faith with the addition of the teachings of Christ. 

Maybe better stated, the Jewish faith, is the history of Christianity by way of Christ's Jewish lineage. His faith and physical ancestors was Jewish.