The Catechism of The Catholic Church begins the section on the Sacraments of Christian Initiation by stating this: The sacraments of Christian initiation - Baptism, Confirmation, and the Eucharist - lay the foundations of every Christian life. "The sharing in the divine nature given to men through the grace of Christ bears a certain likeness to the origin, development, and nourishing of natural life. The faithful are born anew by Baptism, strengthened by the sacrament of Confirmation, and receive in the Eucharist the food of eternal life. By means of these sacraments of Christian initiation, they thus receive in increasing measure the treasures of the divine life and advance toward the perfection of charity."
Christians would agree on this for the most part. Our own Protestant background adhered to the sacredness of these sacraments in part, but as we have come to understand there is a deeper more profound sacredness given to these sacraments that has been protected within The Catholic Church. We could attempt to rewrite what Church Fathers and current history theologians have eloquently stated, but that just doesn't seem prudent. Therefore, we refer you to these links for your own consideration.
The Catechism of the Catholic Church:
http://www.vatican.va/archive/ENG0015/__P3E.HTM through http://www.vatican.va/archive/ENG0015/__P44.HTM
Bishop Robert Barron on the Sacraments of Christian Initiation:
http://www.wordonfire.org/resources/video/the-sacrament-of-baptism/276/ (if you don't take time to read or listen to all the links, listen to this one.)