This book explores and explains the Catholic doctrine of the Mass as a re-enactment (representation) of the one sacrifice (sacrifice) of Christ on the cross, which occurred without blood on the altar of the church. The author explains how the whole Church, as the Mystical Body of Christ, is united with Christ as Priest and Victim, in this offering to God the Father. It places the Mass at the center of Christian life and explains its profound theological significance, beyond a mere communal meal or act of remembrance.