Reply Obj. 2: As Christ's Passion benefits all, for the forgiveness of sin and the attaining of grace and glory, whereas it produces no effect except in those who are united with Christ's Passion through faith and charity, so likewise this sacrifice, which is the memorial of our Lord's Passion, has no effect except in those who are united with this sacrament through faith and charity. Hence Augustine says to Renatus (De Anima et ejus origine i): "Who may offer Christ's body except for them who are Christ's members?" Hence in the Canon of the Mass no prayer is made for them who are outside the pale of the Church. But it benefits them who are members, more or less, according to the measure of their devotion.
Reply Obj. 3: Receiving is of the very nature of the sacrament, but offering belongs to the nature of sacrifice: consequently, when one or even several receive the body of Christ, no help accrues to others. In like fashion even when the priest consecrates several hosts in one mass, the effect of this sacrament is not increased, since there is only one sacrifice; because there is no more power in several hosts than in one, since there is only one Christ present under all the hosts and under one. Hence, neither will any one receive greater effect from the sacrament by taking many consecrated hosts in one mass. But the oblation of the sacrifice is multiplied in several masses, and therefore the effect of the sacrifice and of the sacrament is multiplied. _______________________
EIGHTH ARTICLE [III, Q. 79, Art. 8]
Whether the Effect of This Sacrament Is Hindered by Venial Sin?
Objection 1: It seems that the effect of this sacrament is not hindered by venial sin. For Augustine (Tract. xxvi in Joan.), commenting on John 6:52, "If any man eat of this bread," etc., says: "Eat the heavenly bread spiritually; bring innocence to the altar; your sins, though they be daily, let them not be deadly." From this it is evident that venial sins, which are called daily sins, do not prevent spiritual eating. But they who eat spiritually, receive the effect of this sacrament. Therefore, venial sins do not hinder the effect of this sacrament.
Obj. 2: Further, this sacrament is not less powerful than Baptism. But, as stated above (Q. 69, AA. 9, 10), only pretense checks the effect of Baptism, and venial sins do not belong to pretense; because according to Wis. 1:5: "the Holy Spirit of discipline will flee from the deceitful," yet He is not put to flight by venial sins. Therefore neither do venial sins hinder the effect of this sacrament.
Obj. 3: Further, nothing which is removed by the action of any cause, can hinder the effect of such cause. But venial sins are taken away by this sacrament. Therefore, they do not hinder its effect.
On the contrary, Damascene says (De Fide Orth. iv): "The fire of that desire which is within us, being kindled by the burning coal," i.e. this sacrament, "will consume our sins, and enlighten our hearts, so that we shall be inflamed and made godlike." But the fire of our desire or love is hindered by venial sins, which hinder the fervor of charity, as was shown in the Second Part (I-II, Q. 81, A. 4; II-II, Q. 24, A. 10). Therefore venial sins hinder the effect of this sacrament.
I answer that, Venial sins can be taken in two ways: first of all as past, secondly as in the act of being committed. Venial sins taken in the first way do not in any way hinder the effect of this sacrament. For it can come to pass that after many venial sins a man may approach devoutly to this sacrament and fully secure its effect. Considered in the second way venial sins do not utterly hinder the effect of this sacrament, but merely in part. For, it has been stated above (A. 1), that the effect of this sacrament is not only the obtaining of habitual grace or charity, but also a certain actual refreshment of spiritual sweetness: which is indeed hindered if anyone approach to this sacrament with mind distracted through venial sins; but the increase of habitual grace or of charity is not taken away.
Reply Obj. 1: He that approaches this sacrament with actual venial sin, eats spiritually indeed, in habit but not in act: and therefore he shares in the habitual effect of the sacrament, but not in its actual effect.