The Mass

Attending Sunday Mass (and the Holy Days of Obligation) are requirements of our faith. But more than that, the celebration of The Sacred Mysteries is what binds the universal Church. The Eucharist, is the source and summit of our faith. It is the Real Presence, that actual appearance of Jesus' body and blood in our lives, the collision between humanity and the Divine. It is a foretaste of heaven.

Here is catechism on Mass. Here is catechism on the Eucharist. 

This is a very simple and family friendly expalnation of the Mass.