In my new book, Behold Your Mother - A Biblical and Historical Defense of the Marian Doctrines, I give eight reasons for belief in the Immaculate Conception:
1. Mary is revealed to be "full of grace" in Luke 1:28.
2. Mary is revealed to be the fulfillment of the prophetic "Daughter of Zion" of Zech. 2:10; Zeph. 3:14-16; Isaiah 12:1-6, etc.
3. Mary is revealed...