Isaiah 1:21 (a) This word is used to describe Jerusalem when she was living in idolatry and in corrupt relationship with the rich nations around her. The affections of her heart were taken away from the living and the true GOD, and she became enamored of the idols of other peoples. (See also Jeremiah 2:20; Ezekiel 16:15; Hosea 2:5).
Revelation 17:5 (a) Babylon is a type of the Roman Catholic Church. This is so stated by many historians and scholars who are authorized to explain the Scriptures. Many large denominations have hived off from this church, and have carried with them many of the traditions and practices of the mother church. Many of these follow the practice of the mother church in seeking the favor and the gifts of the world.