Today’s Catechism sections discuss the effects, or fruits of the Holy Eucharist. Supporting material comes from the “Summa Theologica”.
The fruits of Holy Communion
1391 Holy Communion augments our union with Christ. The principal fruit of receiving the Eucharist in Holy Communion is an intimate union with Christ Jesus. Indeed, the Lord said: "He who eats my flesh and drinks my blood abides in me, and I in him."223 Life in Christ has its foundation in the Eucharistic banquet: "As the living Father sent me, and I live because of the Father, so he who eats me will live because of me."224
On the feasts of the Lord, when the faithful receive the Body of the Son, they proclaim to one another the Good News that the first fruits of life have been given, as when the angel said to Mary Magdalene, "Christ is risen!" Now too are life and resurrection conferred on whoever receives Christ.225
1392 What material food produces in our bodily life, Holy Communion wonderfully achieves in our spiritual life. Communion with the flesh of the risen Christ, a flesh "given life and giving life through the Holy Spirit,"226 preserves, increases, and renews the life of grace received at Baptism. This growth in Christian life needs the nourishment of Eucharistic Communion, the bread for our pilgrimage until the moment of death, when it will be given to us as viaticum.
1393 Holy Communion separates us from sin. The body of Christ we receive in Holy Communion is "given up for us," and the blood we drink "shed for the many for the forgiveness of sins." For this reason the Eucharist cannot unite us to Christ without at the same time cleansing us from past sins and preserving us from future sins:
For as often as we eat this bread and drink the cup, we proclaim the death of the Lord. If we proclaim the Lord's death, we proclaim the forgiveness of sins. If, as often as his blood is poured out, it is poured for the forgiveness of sins, I should always receive it, so that it may always forgive my sins. Because I always sin, I should always have a remedy.227
1394 As bodily nourishment restores lost strength, so the Eucharist strengthens our charity, which tends to be weakened in daily life; and this living charity wipes away venial sins.228 By giving himself to us Christ revives our love and enables us to break our disordered attachments to creatures and root ourselves in him:
Since Christ died for us out of love, when we celebrate the memorial of his death at the moment of sacrifice we ask that love may be granted to us by the coming of the Holy Spirit. We humbly pray that in the strength of this love by which Christ willed to die for us, we, by receiving the gift of the Holy Spirit, may be able to consider the world as crucified for us, and to be ourselves as crucified to the world.... Having received the gift of love, let us die to sin and live for God.229
1395 By the same charity that it enkindles in us, the Eucharist preserves us from future mortal sins. The more we share the life of Christ and progress in his friendship, the more difficult it is to break away from him by mortal sin. The Eucharist is not ordered to the forgiveness of mortal sins - that is proper to the sacrament of Reconciliation. The Eucharist is properly the sacrament of those who are in full communion with the Church.
1396 The unity of the Mystical Body: the Eucharist makes the Church. Those who receive the Eucharist are united more closely to Christ. Through it Christ unites them to all the faithful in one body - the Church. Communion renews, strengthens, and deepens this incorporation into the Church, already achieved by Baptism. In Baptism we have been called to form but one body.230 The Eucharist fulfills this call: "The cup of blessing which we bless, is it not a participation in the blood of Christ? The bread which we break, is it not a participation in the body of Christ? Because there is one bread, we who are many are one body, for we all partake of the one bread:"231
If you are the body and members of Christ, then it is your sacrament that is placed on the table of the Lord; it is your sacrament that you receive. To that which you are you respond "Amen" ("yes, it is true!") and by responding to it you assent to it. For you hear the words, "the Body of Christ" and respond "Amen." Be then a member of the Body of Christ that your Amen may be true.232
1397 The Eucharist commits us to the poor. To receive in truth the Body and Blood of Christ given up for us, we must recognize Christ in the poorest, his brethren:
You have tasted the Blood of the Lord, yet you do not recognize your brother,.... You dishonor this table when you do not judge worthy of sharing your food someone judged worthy to take part in this meal.... God freed you from all your sins and invited you here, but you have not become more merciful.233
1398 The Eucharist and the unity of Christians. Before the greatness of this mystery St. Augustine exclaims, "O sacrament of devotion! O sign of unity! O bond of charity!"234 The more painful the experience of the divisions in the Church which break the common participation in the table of the Lord, the more urgent are our prayers to the Lord that the time of complete unity among all who believe in him may return.
1399 The Eastern churches that are not in full communion with the Catholic Church celebrate the Eucharist with great love. "These Churches, although separated from us, yet possess true sacraments, above all - by apostolic succession - the priesthood and the Eucharist, whereby they are still joined to us in closest intimacy." A certain communion in sacris, and so in the Eucharist, "given suitable circumstances and the approval of Church authority, is not merely possible but is encouraged."235
1400 Ecclesial communities derived from the Reformation and separated from the Catholic Church, "have not preserved the proper reality of the Eucharistic mystery in its fullness, especially because of the absence of the sacrament of Holy Orders."236 It is for this reason that Eucharistic intercommunion with these communities is not possible for the Catholic Church. However these ecclesial communities, "when they commemorate the Lord's death and resurrection in the Holy Supper . . . profess that it signifies life in communion with Christ and await his coming in glory."237
1401 When, in the Ordinary's judgment, a grave necessity arises, Catholic ministers may give the sacraments of Eucharist, Penance, and Anointing of the Sick to other Christians not in full communion with the Catholic Church, who ask for them of their own will, provided they give evidence of holding the Catholic faith regarding these sacraments and possess the required dispositions.238
1416 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.
1417 The Church warmly recommends that the faithful receive Holy Communion each time they participate in the celebration of the Eucharist; she obliges them to do so at least once a year.
1418 Because Christ himself is present in the sacrament of the altar, he is to be honored with the worship of adoration. "To visit the Blessed Sacrament is . . . a proof of gratitude, an expression of love, and a duty of adoration toward Christ our Lord" (Paul VI, MF 66).
St. Thomas Aquinas explains the forgiveness of venial sins through the reception of the Holy Eucharist in the “Summa Theologica” (3, 79, 4).
Article 4. Whether venial sins are forgiven through this sacrament?
Objection 1. It seems that venial sins are not forgiven by this sacrament, because this is the "sacrament of charity," as Augustine says (Tract. xxvi in Joan.). But venial sins are not contrary to charity, as was shown in I-II, 88, 1,2; II-II, 24, 10. Therefore, since contrary is taken away by its contrary, it seems that venial sins are not forgiven by this sacrament.
Objection 2. Further, if venial sins be forgiven by this sacrament, then all of them are forgiven for the same reason as one is. But it does not appear that all are forgiven, because thus one might frequently be without any venial sin, against what is said in 1 John 1:8: "If we say that we have no sin, we deceive ourselves." Therefore no venial sin is forgiven by this sacrament.
Objection 3. Further, contraries mutually exclude each other. But venial sins do not forbid the receiving of this sacrament: because Augustine says on the words, "If any man eat of it he shall [Vulgate: 'may'] not die for ever" (John 6:50): "Bring innocence to the altar: your sins, though they be daily . . . let them not be deadly." Therefore neither are venial sins taken away by this sacrament.
On the contrary, Innocent III says (De S. Alt. Myst. iv) that this sacrament "blots out venial sins, and wards off mortal sins."
I answer that, Two things may be considered in this sacrament, to wit, the sacrament itself, and the reality of the sacrament: and it appears from both that this sacrament has the power of forgiving venial sins. For this sacrament is received under the form of nourishing food. Now nourishment from food is requisite for the body to make good the daily waste caused by the action of natural heat. But something is also lost daily of our spirituality from the heat of concupiscence through venial sins, which lessen the fervor of charity, as was shown in the II-II, 24, 10. And therefore it belongs to this sacrament to forgive venial sins. Hence Ambrose says (De Sacram. v) that this daily bread is taken "as a remedy against daily infirmity."
The reality of this sacrament is charity, not only as to its habit, but also as to its act, which is kindled in this sacrament; and by this means venial sins are forgiven. Consequently, it is manifest that venial sins are forgiven by the power of this sacrament.
Reply to Objection 1. Venial sins, although not opposed to the habit of charity, are nevertheless opposed to the fervor of its act, which act is kindled by this sacrament; by reason of which act venial sins are blotted out.
Reply to Objection 1. The passage quoted is not to be understood as if a man could not at some time be without all guilt of venial sin: but that the just do not pass through this life without committing venial sins.
Reply to Objection 3. The power of charity, to which this sacrament belongs, is greater than that of venial sins: because charity by its act takes away venial sins, which nevertheless cannot entirely hinder the act of charity. And the same holds good of this sacrament.
223 ⇒ Jn 6:56.
224 ⇒ Jn 6:57.
225 Fanqith, Syriac Office of Antioch, Vol. 1, Commun., 237 a-b.
226 PO 5.
227 St. Ambrose, De Sacr. 4, 6, 28: PL 16, 446; cf. ⇒ 1 Cor 11:26.
228 Cf. Council of Trent (1551): DS 1638.
229 St. Fulgentius of Ruspe, Contra Fab. 28, 16-19: CCL 19A, 813-814.
230 Cf. ⇒ 1 Cor 12:13.
231 ⇒ 1 Cor 10:16-17.
232 St. Augustine, Sermo 272: PL 38, 1247.
233 St. John Chrysostom, Hom. in 1 Cor. 27, 4: PG 61, 229-230; cf. ⇒ Mt 25:40.
234 St. Augustine, In Jo. ev. 26, 13: PL 35, 1613; cf. SC 47.
235 UR 15 # 2; cf. ⇒ CIC, can. 844 # 3.
236 UR 22 # 3.
237 UR 22 # 3.
238 Cf. ⇒ CIC, can. 844 # 4.