A number of my Protestant friends who have studied Greek use grape juice at their communion service. Why does the Catholic Church use wine?
The Catholic and Orthodox Churches use wine because the Gospels of Matthew, Mark, and Luke indicate that Jesus used “the fruit of the vine ” at the Last Supper. That probably meant wine at least, that is how these Churches understood those texts for almost 1,500 years before the religious ancestors of your friends started to use grape juice.