What is Mystery Babylon?
Revelation 17:5, calls the church of the end-time (the coming one-word religion/church), "Mystery Babylon the great, the mother of harlots and of the abominations of the earth."
And on her forehead a name was written:
MYSTERY, BABYLON THE GREAT,
THE MOTHER OF HARLOTS
AND OF THE ABOMINATIONS
OF THE EARTH.
Some theologians make a strong case that the Catholicism will be at the very head of the end time church. In Revelation 17 John was taken away into the wilderness and he saw a woman riding upon the beast. In Zechariah we see the same woman pictured in a barrel and carried by two other women into power in Babylon. The other women had wings like a stork – an unclean bird. The two who women will carry Catholicism into power will be apostate Christianity and apostate Judaism. If you carefully observe the tenants of Catholicism it has some semblances of Christianity, the priesthood of Judaism, and the idols of the heathen. It is compatible with every religion on earth today.
Pope Benedict XVI called for Christians 'to open their arms and hearts" to Muslim immigrants and "to dialogue" with them on religious issues. The Pope told participants that the Catholic Church is "increasingly aware" that "interreligious dialogue is a part of its commitment to the service of humanity in the modern world." 
There was a time that the Catholic Church persecuted Jews but today we hear talk about the church making its "peace"with the Jews. More recently when the pope went to Jerusalm, the Jews who though the years hated Christianity welcomed the pope with open arms.