The Catholic Church recognizes seven sacraments. Of these, the Eucharist stands apart. St. Thomas Aquinas called it the “Sacrament of Sacraments.”

The Eucharist is the Real Presence of Jesus Christ, Body and Blood, Soul and Divinity, under the appearance of bread and wine. The Eucharist is also referred to as “Holy Communion.” 

“Communion” comes from the Latin communio, which means “to be in union with.” According to the Catechism of the Catholic Church, the Church refers to the Eucharist by this name “because by this sacrament we unite ourselves to Christ, who makes us sharers in his Body and Blood to form a single body” (1331).

The Church teaches that anyone who receives Jesus in the Eucharist also receives “the pledge of glory with him” (1419). 

The Catechism says that participating in the Eucharist “identifies us with his Heart, sustains our strength along the pilgrimage of this life, makes us long for eternal life, and unites us even now to the Church in heaven, the Blessed Virgin Mary, and all the saints” (1419).

The Church also teaches that receiving the Eucharist “increases the communicant’s union with the Lord, forgives his venial sins, and preserves him from grave sins” (1416).”

Receiving the Eucharist can transform one’s spiritual life. That’s why Pope Francis said in his apostolic exhortation Evangelii Gaudium, the Eucharist “is not a prize for the perfect but a powerful medicine and nourishment for the weak.”

At the same time, the Church draws on the words of Scripture in setting forth requirements for receiving Holy Communion. As St. Paul tells us, “Whoever, therefore, eats the bread or drinks the cup of the Lord in an unworthy manner will be guilty of profaning the Body and Blood of the Lord. Let a man examine himself, and so eat of the Bread and drink of the cup. For any one who eats and drinks without discerning the body eats and drinks judgment upon himself.” (1 Corinthians 11:27-28).

The Church teaches that there are two basic requirements Catholics must meet in order to receive Holy Communion worthily.

First, one must be in a state of grace.

To be in a “state of grace” means to be free from mortal sin. As the Catechism states, “Anyone aware of having sinned mortally must not receive Communion without having received absolution in the sacrament of penance” (1415).

What is a mortal sin? The Catechism explains that a mortal sin “destroys charity in the heart of man by a grave violation of God's law; it turns man away from God” (1855).

For a sin to be mortal, or deadly, one must be aware that the act is sinful and conscientiously commit it anyway.

Examples of mortal sins include: murder, adultery, fornication, homosexual acts, theft, abortion, euthanasia, pornography, and taking advantage of the poor. The Church teaches that intentionally skipping Mass on a Sunday or holy day of obligation when one is able to attend also is a mortal sin.

The 1983 Code of Canon Law emphasizes this requirement for receiving Holy Communion when it states: “A person who is conscious of a grave sin is not to … receive the Body of the Lord without prior sacramental confession unless a grave reason is present and there is no opportunity of confessing; in this case the person is to be mindful of the obligation to make an act of perfect contrition, including the intention of confessing as soon as possible” (916).

The U.S. bishops, in the document they adopted in November 2021 titled, “The Mystery of the Eucharist in the Life of the Church,” elaborate on this important point.

“To receive the Body and Blood of Christ while in a state of mortal sin represents a contradiction,” the document states. “The person who, by his or her own action, has broken communion with Christ and his Church but receives the Blessed Sacrament, acts incoherently, both claiming and rejecting communion at the same time. It is thus a counter sign, a lie — it expresses a communion that in fact has been broken.”

The bishops' document goes on to say that the sacrament of penance "provides us with the opportunity to recover the gift of sanctifying grace and to be restored to full communion with God and the Church. All the sacrament requires of us as penitents is that we have contrition for our sins, resolve not to sin again, confess our sins, receive sacramental absolution, and do the assigned penance.”

The second requirement for receiving Holy Communion is to observe the Eucharistic fast.

Canon law states, “One who is to receive the most Holy Eucharist is to abstain from any food or drink, with the exception only of water and medicine, for at least the period of one hour before Holy Communion” (919). 

Elderly people, those who are ill, and their caretakers are excused from the Eucharistic fast (191 §3). Priests and deacons may not dispense one obligated by the Eucharistic fast unless the bishop has expressly granted such power to them (89).