Is it valid to use grape juice at Communion?

In the Bible there is a routine reference to the fruit of the vine. Which is a direct reference to Jesus. Grape juice is used today because it and only it can be representative of the Blood of Jesus. In Biblical times the grapes were fermented, which made for strong drink ( wine) as we would know it today. But the difference in the time of Jesus is that the fermented grapes were mixed with three parts water to one part fermented grapes, which would weaken the drink. The juice from the grape is the representation of the Blood of Jesus. So in that case it is not only proper, but also a Biblical must that the church use grape juice.

lets see. they had water, they had grapes, oops they could have made grape juice. nothing in the bible was done by accident. Jesus chose wine for a reason. we may not understand what that reason was but we should defend and honor his choice....

What exactly does the Bible command regarding communion? 1 Cor 11:25, "In the same manner He also took the cup after supper, saying, 'This cup is the new covenant in My blood. This do, as often as you drink it, in remembrance of Me.'"

That's pretty much it. If someone can point to a reference with more specific instructions, please post. But from that, I don't see how you could prove Biblically that it must be either wine OR grape juice. It just says we should drink from a cup.

The Gospels don't actually say the cup contained wine. They say, "the fruit of the vine", which could be wine or grape juice. But in any case, nothing in the Bible says that the contents of the cup are an essential component of the sacrament. There are many details of the ceremony as Jesus performed it. In the absence of specific commands, which of these details are essential and which are irrelevant? The Bible clearly says that the Last Supper took place on Passover, yet I've never heard a Christian say that we can only perform the sacrament on Passover. We are told that 13 people were present, yet I've never heard a Christian say that the ceremony is invalid unless exactly 13 people are present. Every church I've ever been in serves the wine or grape juice in glasses, while the Bible clearly says that Jesus used a cup. Etc. Perhaps you'll say I'm just bringing up silly and ridiculous points. But why is the contents of the cup essential but the cup itself is not? Who says, and on what basis?

I would consider it distinctly odd and irreverent to have a communion service with iced tea and donuts. But I really can't make a scriptural argument against that, I just wouldn't think it "feels right".

The United Methodist Church uses grape juice for communion. Here's their reasoning.

The United Methodist Book of Worship says, "Although the historic and ecumenical Christian practice has been to use wine, the use of unfermented grape juice by The United Methodist Church and its predecessors since the late nineteenth century expresses pastoral concern for recovering alcoholics, enables the participation of children and youth, and supports the church's witness of abstinence."

So no, no Biblical reason, just a practical reason.

I would say it is not valid. The wine at the Last Supper — Jesus' Passover celebration — was fermented because that was the tradition. It was an oral tradition later codified in the Mishnah, but it was still what Christ did, so it should be when we Do this in remembrance. It's not simply an act, it's a re-creation. I can see that the theology of the Eucharist looms large in the answer for "valid" or "invalid"!

The reason there is no prescription in the Bible is because wine is wine: grape juice fermented anyway so there wasn't a choice. It would never had occurred to the writers to say otherwise because grape juice didn't really exist (only as a precursor to wine). There is no proscription either, so there is no basis not to use wine. Indeed, Paul admonishes Timothy in 1 Tim 5:23 to take wine.

Having just checked, the Catholic Code of Canon Law (Can. 924) and the Canons of the Church of England (Can. B17) do prescribe wine. Other Churches may do likewise — and in those Churches it is certainly not valid to use unfermented juice.

To answer Narnian's edit, if there is no alternative then in extremis of course something else can be used. But if wine can conveniently be obtained, then to do otherwise is not valid.

The earliest recorded formulation of the Lord's Supper reads:

For I received from the Lord what I also delivered to you, that the Lord Jesus on the night when he was betrayed took bread, and when he had given thanks, he broke it, and said, “This is my body which is for you. Do this in remembrance of me.” In the same way also he took the cup, after supper, saying, “This cup is the new covenant in my blood. Do this, as often as you drink it, in remembrance of me.” For as often as you eat this bread and drink the cup, you proclaim the Lord's death until he comes.—1^st Corinthians 11:23-26 (ESV)

These are the words that many Protestant denominations use to institute the sacrament. Which cup was Jesus talking about? It was almost certainly one of the cups of wine that are traditionally associated with the Passover celebration. While there's an off-chance it was just grape juice, it's more likely to have been strong wine diluted with water.

In contrast with the cup, we can be pretty certain that the bread was unleavened as befits the Passover. However, Christian tradition does not universally require the bread at the Lord's Supper to be unleavened. The issue of what type of bread to use turned out to be the final straw that precipitated the Great Schism.

So can we drink grape juice instead of wine for the Lord's Supper? I'll let Paul take a crack at that question:

“All things are lawful,” but not all things are helpful. “All things are lawful,” but not all things build up. Let no one seek his own good, but the good of his neighbor. Eat whatever is sold in the meat market without raising any question on the ground of conscience. For “the earth is the Lord's, and the fullness thereof.” If one of the unbelievers invites you to dinner and you are disposed to go, eat whatever is set before you without raising any question on the ground of conscience. But if someone says to you, “This has been offered in sacrifice,” then do not eat it, for the sake of the one who informed you, and for the sake of conscience—I do not mean your conscience, but his. For why should my liberty be determined by someone else's conscience? If I partake with thankfulness, why am I denounced because of that for which I give thanks?

So, whether you eat or drink, or whatever you do, do all to the glory of God. Give no offense to Jews or to Greeks or to the church of God, just as I try to please everyone in everything I do, not seeking my own advantage, but that of many, that they may be saved.—1^st Corinthians 10:23-33 (ESV)

The churches I normally attend use grape juice. But when I go to a church that uses wine, I drink up. I imagine the reverse is true. As to whether communion at my church is valid: that's another question entirely.