346. The fourth commandment of the Church is, "To receive the Holy Eucharist during Easter time". Christ said to His disciples: "Except you eat the Flesh of the Son of Man and drink His Blood, you shall not have life in you" (Jo. VI, 54). It is therefore clearly the duty of all the faithful, as it is also their inestimable privilege, sometimes to receive Holy Communion. We have seen (n. 260) how often the early Christians received it; how as fervor gradually cooled, its reception had to he commanded, and was at last fixed, by the Fourth Lateran Council, at once at least every year. The most appropriate time is evidently about Easter, when we commemorate both its institution and the Sacrifice of Calvary, which it perpetuates (n. 252); and this time is prescribed by the Church. But, owing to the fewness of priests compared to the large numbers of the faithful in most parts of this country, the period has been made to extend here from the first Sunday of Lent to Trinity Sunday included. Whoever neglects this yearly duty commits a grievous sin of disobedience to the Church, and remains, after the period is elapsed, under the obligation of communicating as soon as he can.
347. That Christ intended this precious Sacrament to be much more frequently received than once a year, is apparent from the form He gave it, which is that of bread, the most common food of men. The practice of the early Christians shows that the matter was so understood by the Apostles and their successors. Monthly and, still more, weekly Communion is recommended to all the faithful; and St. Angustine writes:" Live in such a manner as to be able to receive every day" (Serm. 28). The Catechism of Trent remarks that the words, "Thou sinnest daily, receive daily", convey the sentiments, not only of St. Augustine, to whom they are ascribed, but of all the Fathers who have written on the subject (p. 170).
The effects of this Sacrament are certainly such as most highly to recommend its frequent reception: (a) Our Blessed Saviour is the first to proclaim them, saying: "He that eateth My Flesh, and drinketh My Blood, hath everlasting life, and I will raise him up on the last day. He abideth in Me, and I in him. . . . He that eateth Me, the same also shall live by Me", etc. (Jo. VI, 55, 58). (b) In the other Sacraments we receive grace, in this the Fountain of all grace. (c) It is the main support of the spiritual life, as is indicated by the species of bread, the staff of life. (d) The Council of Trent calls it "an antidote, by which we are freed from daily faults and preserved from mortal sin" (Sess. 13, c. 2). This means that our daily faults are pardoned by it; as St. Ambrose affirms, saying: "This daily Bread is taken as a remedy for daily infirmity" (De Sacr. Lib. IV, c. 6). (e) It represses concupiscence, wherefore it is called "The Bread of Angels" (Ps. 77). (f) It procures abundant grace for the Christian warfare against the enemies of salvation. Thus St. Cyril records that in his day those who expected to be martyred prepared for it by receiving the Holy Communion (Cat. Conc. Trid. p. 166). 330 The Fourth Commandment of the Church.
Those who cannot receive the Blessed Sacrament as often as they might wish, can secure a considerable portion of its advantages by receiving what is called spiritual Communion; this can be done at any time, and consists in eliciting fervent desires of this Holy Sacrament.
348. Sacramental Communion being so sacred an action requires careful preparation. The manner of making this preparation is always diligently taught to the children before the day of their First Communion, and is laid down in approved prayer-books. The chief points are: (a) A diligent examination of conscience; as the Apostle directs: "Let a man prove himself, and so let him eat of that Bread and drink of the Chalice (n. 250). For he that eateth and drinketh unworthily, eateth and drinketh judgment to himself, not discerning the Body of the Lord" (1 Cor. XI, 28, 29). If no mortal sin can be found in the soul, confession, though commendable, is not necessary; but if a mortal sin be there it must of course first be removed, and this must, if possible, be done by confession and absolution; for the Council of Trent has decreed that no one having an opportunity of recurring to a confessor, however contrite he may deem himself, is to approach the Holy Eucharist until he has been purified by a sacramental confession. (Sess. 13, can. 11.) (b) The pardon of enemies: "Go first and be reconciled to thy brother" (Matt. V 25); grievous hatred would make the Communion unworthy. (c) Sentiments of humility, of which the Church reminds us by the words: "Lord, I am not worthy that Thou shouldst enter under my roof" (Matt. VIII, 8). (d) Sentiments of great confidence: "Only say the word, and my soul shall be healed". (e) Acts of faith, desire, and sincere love: "Lord, Thou knowest that I love Thee". (f) By a special precept of the Church the communicant, except when he receives the Blessed Sacrament by way of Viaticum in danger of death, should be fasting from all food and drink since the midnight preceding.