Why do we celebrate the solemnity of the Immaculate Conception?
First, what does the title connote? Mary as the Immaculate Conception connotes total unity with God who is our first beginning and our last end. Mary embodies the new man as God wishes it to be, sinful and undefiled like the Father.
Second, the title opens for us a world of hope of what we should be. We may have fallen from the state of holiness, but God has given us a concrete model to learn from, that hopefully in this world, we may struggle through to imbue holiness in our being. It also connotes that all the things we do in this world should be "sanctified" or made holy. Imagine if all people would travel in this world with this in mind. Nobody would be traveling in sin and no one should suffer as a consequence of sin.
Finally, Mary's Immaculate Conception always points to the reality of Jesus, our beloved Messiah. She was prepared by God as a living tabernacle, undefiled, for her Son. So too must we strive to bring Jesus and His work into the world.
Mama Mary, pray for us, your children. Lead us to your son, Jesus Christ, Amen!