Why do liberals/leftists have a visceral hatred of Christianity even though it has almost no influence today ?

The core liberal belief is that the human person is the ultimate source of freedom and goodness, and so must be emancipated not only from restrictive political and social systems but from the Church, religion and even God Himself. Thus liberalism is above all a spiritual rebellion – not just a political or social ideology. On the surface it seems odd that liberals in the postmodern era tend to identify with the cause of Islam, since that faith is antithetical to most liberal values. But Islam has long been the sworn enemy of Christianity, and it is Christianity with which liberalism has been at war for three centuries.