The Catechism of the Catholic Church states in CCC #2181 - The Sunday Eucharist is the foundation and confirmation of all Christian practice. For this reason the faithful are obliged to participate in the Eucharist on days of obligation, unless excused for a serious reason (for example, illness, the care of infants) or dispensed by their own pastor.119 Those who deliberately fail in this obligation commit a grave sin.
When a person negligently “bags Mass,” to go shopping, catch-up on work, sleep a few extra hours, attend a social event, or not interrupt vacation, the person is allowing something to take the place of God. Something becomes more valuable than the Holy Eucharist . . .Read More
What is grave sin?
A serious, grave or mortal sin is the knowing and willful violation of God's law in a serious matter, for example, idolatry, adultery, murder, slander. These are all things gravely contrary to the love we owe God and, because of Him, our neighbor.
Mortal sin is called mortal because it is the "spiritual" death of the soul (separation from God). If we are in the state of grace it loses this supernatural life for us. If we die without repenting we will lose Him for eternity. However, by turning our hearts back to Him and receiving the Sacrament of Penance we are restored to His friendship. Catholics are not allowed to receive Communion if they have unconfessed mortal sins.
Thousands, if not millions of Catholics have abandoned the sacrament of Penance. Some reject the Church’s teaching on the sacrament and rely on their own opinions and interpretations, while others suffer from the lack of proper faith formation. In any event, proper disposition toward, and reverence for the Eucharist must be restored by informing Catholics of the error of receiving Communion while not in a state of grace.
Only when properly disposed to the sacrament of Penance, can we be restored to a state of grace and thus become worthy to approach and receive our Lord in the Eucharist!
COME BACK TO CONFESSION! Let’s repent of our sins and return to practicing our faith in accordance with the teachings of the Church. Let us show thanks for the grace Christ provides for us through His sacraments by humbly accepting these gifts of love!