If someone is planning to receive our Lord in Holy Communion at Mass, there are several requirements to keep in mind:
1. You must be a baptized Catholic who has already made his/her First Holy Communion.
2. You must not have ANY mortal sin on your soul that has not been absolved in Sacramental Confession. To receive Holy Communion in the state of sin without SACRAMENTAL confession is a sacrilege and a most serious sin. You will get no graces from Holy Communion if you do – only the most severe punishments. This was made manifestly clear in Canon 856 of the 1917 Code of Canon Law. St. Cyril of Alexandria explains further the gravity when he says, “They who make a sacrilegious Communion receive Satan and Jesus Christ into their heart. Satan, that they may let him rule, and Jesus Christ that they may offer Him in sacrifice to Satan.”
3. Observe the Eucharistic Fast before Holy Communion
4. Pay attention at Mass and be especially devout from the time of the Offertory through the Consecration and until the Priest’s Communion at the end of the Canon.
5. Approach Holy Communion reverently, dressed modestly and desiring to receive our Lord who you profess is present in the Eucharistic Host in His Body, Blood, Soul, AND Divinity under the appearance (but not substance) of bread. You must receive Holy Communion reverently as well.
6. And you must approach the Sacred Altar with a proper intention. We must have a “right and pious intention.” St. Pius X lists several intentions which are not right and pious. They include approaching the altar to receive “through habit, or vanity, or human reasonings.” Thus, receiving Holy Communion just because everyone else is receiving or because we do so only to appear holy to others is not with the right intention. On the contrary, St. Pius X summarizes a right and pious intention as one that seeks “to satisfy the pleasure of God, to be joined with Him more closely in charity and to oppose one’s infirmities and defects with that divine remedy.”
Beyond these necessary conditions, St. Pius X set forth, especially for those who sought to receive Holy Communion very regularly – even daily – more perfect dispositions to strive for when he wrote: “It is especially expedient that those who practice frequent and daily communion be free from venial sins, at least from such as are fully deliberate, and any affection thereto.” As theologians have commented subsequently, there is a difference between venial sins that are fully deliberate and those venial sins that are not fully deliberate, and which we frequently call imperfections.