A lot of liberal Jews care more about liberalism than they do about Judism. Liberalism tends to hate Christianity. I don't think it has anything to do with being Jews.
Except that organized Judaism explicitly rejects Jesus as the Messiah. So, if you believe that Jesus is God, then organized Judaism has rejected God in His human manifestation - - as the Messiah of the Jews and "Son of God" for the Gentiles. There are consequences of formally rejecting the Messiah - one of the consequences for Judaism is that it has lost its way morally; the great majority of Jews are very liberal - in direct oppostion to God's law on basic issues such as abortion, homosexuality, assisted suicide (or legalized murder, to use a less PC term).