Perhaps the chief theological difference between Protestants and Roman Catholics/Eastern Orthodox is that the latter believe that the grace necessary for salvation is dispensed through sacraments, which must be “valid” in order to have a saving effect. While the personal quality and faithfulness of a man is immaterial in his ability to conduct valid baptisms or to conduct the Lord’s Supper, such a man must be validly ordained in order to loose sins in confession and turn the bread into Christ’s body.
In Irenaeus’ Against Heresies Book 4, Chapter 18 (Chapters 4 through 6) the topic of the Lord’s Supper being invalidated comes up. Ironically, Irenaues fails to give the standard Roman Catholic defense of what makes a sacrament valid. Instead, he argues that someone who does not have the correct, orthodox faith cannot conduct a valid sacrament.
In the following, Irenaeus’ words are in italics and mine are in between.
For it behooves us to make an oblation to God, and in all things to be found grateful to God our Maker, in a pure mind, and in faith without hypocrisy, in well-grounded hope, in fervent love, offering the first-fruits of His own created things. And the Church alone offers this pure oblation to the Creator, offering to Him, with giving of thanks, [the things taken] from His creation. But the Jews do not offer thus: for their hands are full of blood; for they have not received the Word, through whom it is offered to God. Nor, again, do any of the conventicles (synagogæ) of the heretics [offer valid sacrifices]. For some, by maintaining that the Father is different from the Creator, do, when they offer to Him what belongs to this creation of ours, set Him forth as being covetous of another’s property, and desirous of what is not His own. Those, again, who maintain that the things around us originated from apostasy, ignorance, and passion, do, while offering unto Him the fruits of ignorance, passion, and apostasy, sin against their Father, rather subjecting Him to insult than giving Him thanks.
All of chapter 18 dwells on the topic that the true sacrifice to God always was and always will be a thankful heart. In short, the heretics by believing in a different God do not give thanks to the true God and thereby do not offer true sacrifices.
But how can they be consistent with themselves, [when they say] that the bread over which thanks have been given is the body of their Lord, and the cup His blood, if they do not call Himself the Son of the Creator of the world, that is, His Word, through whom the wood fructifies, and the fountains gush forth, and the earth gives first the blade, then the ear, then the full grain in the ear. Mark 4:28
Then, again, how can they say that the flesh, which is nourished with the body of the Lord and with His blood, goes to corruption, and does not partake of life? Let them, therefore, either alter their opinion, or cease from offering the things just mentioned.
The heretics cannot rightly call the bread and wine Christ’s body and blood, because they do not believe in the right Christ (many Gnostics did not believe Christ truly came in the flesh) nor that man’s flesh inherits eternal life (which denies Christ’s flesh through digestion becoming part of ours.) Because their doctrine is off, their sacrament has no power and is not a true sacrifice.
But our opinion is in accordance with the Eucharist, and the Eucharist in turn establishes our opinion. For we offer to Him His own, announcing consistently the fellowship and union of the flesh and Spirit. For as the bread, which is produced from the earth, when it receives the invocation of God, is no longer common bread, but the Eucharist, consisting of two realities, earthly and heavenly; so also our bodies, when they receive the Eucharist, are no longer corruptible, having the hope of the resurrection to eternity.
Now we make offering to Him, not as though He stood in need of it, but rendering thanks for His gift, and thus sanctifying what has been created.
The Church, which rightly believes in the true God, enjoys the Eucharist in all of is fullness. The bread and wine take on new natures, “consisting of two realities,” and those of us being nourished with this bread partake in immortality and become endued with it materially.
Conclusion. Irenaeus’ discussion of how the Jews and Gnostics cannot offer real sacrifices gives us a telling picture as to how the early Church viewed sacraments.
For one, being that men like Valentinus were mostly like ordained elders/”priests” at some point (for Tertullian relates that he was considered for the position of bishop in Rome), theoretically many Gnostics could have had been what modern Roman Catholics call validly ordained priests. If they have valid orders, they theoretically have valid sacraments. However, Irenaeus’ does not allow for this because their doctrine was wrong. This puts him in line with Novatian and Cyprian who likewise believed sacraments were invalidated by faithlessness.
Second, Irenaeus’ rationale as to what invalidates a sacrifice (and thereby sacrament) is rather clear. One must believe in the true God in order to faithfully give Him a sacrifice. When it pertains to the Eucharist, refusing the reality that Christ came in the flesh prevents the sacrifice from taking on the specific character of the true Eucharist; it consisting of two realities.
Now, while it is possible that Irenaeus believed that certain Gnostics with valid orders could have validly perform the Lord’s Supper but not have proper thankfulness (and thereby not attain to the benefits of the sacrifice nor honor God with it), this clearly does not appear to follow the overall tone and rationale Irenaeus gives us:
The Jews do not offer a true sacrifice FOR they have not received to Word, not because they lack valid orders from the Apostles. If this whole discussion could have been settled with an appeal to valid orders, likely Irenaeus would have not failed to invoke the idea if he was even aware of it.
And so I apologize if I press my conclusions to strong. I felt I have done so far too much in the past, and I am trying to be increasingly evenhanded. I commend to you, my reader, the citation and links to my commentary so you may evaluate the evidence yourself.