And of course wine's place in the Lord's Supper is clear (Lk. 22:18; 1 Cor. 11:21). While the Bible celebrates wine, it also condemns drunkenness and frequently warns those who would abuse God's gift (Eph. 5:18; Gal 5:19-21; Prov. 23:20, 29-35; Rom. 13:13; 1 Cor. 6:10).
In his book, What Would Jesus Drink, Brad Whittington breaks down the biblical references of alcohol into three types. In all, there are 247 references to alcohol in Scripture. 40 are negative (warnings about drunkenness, potential dangers of alcohol, etc.), 145 are positive (sign of God's blessing, use in worship, etc.), and 62 are neutral (people falsely accused of being drunk, vows of abstinence, etc.) The Bible is anything but silent on the issue of wine. It, like all alcohol, must be treated carefully, seen as a blessing, and received with thanksgiving among those who drink it. It must not be abused. The old saying is true, "Wine is from God, drunkenness is from the Devil."
So why do some churches choose to use unfermented grape juice in the Lord's Supper? We will disregard arguments that present the consumption of wine as sinful, for the Scripture clearly teaches the opposite. But there are valid concerns that people often bring up regarding the use of wine in communion. What of those who struggle with alcoholism? What of those who abstain from all alcohol and whose consciences will not allow them to consume it? Isn't it illegal for children to consume alcohol?
The abuse of and addiction to alcohol is out of control in our culture, and every church is bound to have people that have scarred by this problem. In the case of those who might not be able to handle even a sip of wine, or those whose consciences might not allow the consumption of alcohol, we should seek to help, not hurt. We should strive to maintain a biblical and compassionate approach in all we do as God's people who seek to make disciples in the world. This is why many churches that serve wine for communion also serve grape juice in a separate cup or tray, allowing people who wish to refrain from alcohol continue to participate.
Regarding children, in most of the United States it is not illegal for children to consume alcohol "in the performance of a religious ceremony or service." In our case the Illinois General Assembly makes this clear.
In the end, I believe it is permissible to use grape juice instead of wine for the Lord's Supper, but I do not believe it is best. Wine, as the gift of God and sign of his blessing, was used during the Passover and in the institution of the Lord's Supper, and following that pattern is most biblical. On a related matter, whether the bread used in the Lord's Supper is leavened or not seems less important to me. It must be bread, but the sacrament itself seems to place no emphasis on the unleavened nature of the bread.
There are a variety of ways churches approach this sacrament, and while there are better and worse ways to do it, we should be careful to avoid unnecessary division between or within churches. John Calvin emphasized such grace in his Institutes of the Christian Religion.