“Do This in remembrance of me (Luke 22:19).”

“In the Eucharist the Church is as it were at the foot of the cross with Mary, united with the offering and intercession of Christ (Catechism of the Catholic Church 1370).”

There is nothing so great as the Eucharist. If God had something more precious, He would have given it to us. St. John Vianney

It would be easier for the world to survive without the sun than to do without Holy Mass. St. Pio of Pietrelcina (Padre Pio) 

1. On the nature of the Holy Mass

The sacrifice of Christ and the sacrifice of the Eucharist are one single sacrifice: "The victim is one and the same: the same now offers through the ministry of priests, who then offered himself on the cross; only the manner of offering is different." "And since in this divine sacrifice which is celebrated in the Mass, the same Christ who offered himself once in a bloody manner on the altar of the cross is contained and is offered in an unbloody manner. . . this sacrifice is truly propitiatory" (CCC 1367)

2. On receiving Holy Communion

Anyone who desires to receive Christ in Eucharistic communion must be in the state of grace. Anyone aware of having sinned mortally must not receive communion without having received absolution in the sacrament of penance (CCC 1415)

Communion with the Body and Blood of Christ increases the communicant's union with the Lord, forgives his venial sins, and preserves him from grave sins. Since receiving this sacrament strengthens the bonds of charity between the communicant and Christ, it also reinforces the unity of the Church as the Mystical Body of Christ (CCC 1416)