14 When the hour had come, He reclined at the table, and the apostles with Him. 15 And He said to them, “I have earnestly desired to eat this Passover with you before I suffer; 16 for I say to you, I shall never again eat it until it is fulfilled in the kingdom of God.” 17 And when He had taken a cup and given thanks, He said, “Take this and share it among yourselves; 18 for I say to you, I will not drink of the fruit of the vine from now on until the kingdom of God comes.” 19 And when He had taken some bread and given thanks, He broke it and gave it to them, saying, “This is My body which is given for you; do this in remembrance of Me.” 20 And in the same way He took the cup after they had eaten, saying, “This cup which is poured out for you is the new covenant in My blood. 21 But behold, the hand of the one betraying Me is with [c]Mine on the table. 22 For indeed, the Son of Man is going as it has been determined; but woe to that man by whom He is betrayed!” 23 And they began to discuss among themselves which one of them it might be who was going to do this thing.
Without a doubt, Jews celebrating the Passover in the first century were drinking wine and eating unleavened bread when Jesus instituted the Lord's Supper.
However, it is de rigueur in Evangelicalism to substitute grape juice for wine, the roots of such practice going back to the Temperance Movement. Besides the implicit argument that the consumption of alcohol is immoral, other justifications of the practice include the desire not to be a stumbling block to alcoholics and the desire to include children younger than the legal drinking age, although it is not illegal in the context of Communion.
It is also claimed that since we are not commanded to drink wine, we may, in Christian liberty, substitute grape juice. Many, although not all, who use this argument, strangely do not apply the same logic to baptism and assert that immersion is a requirement, although no such command has been given. They will claim that since the subjectively clear example given in the New Testament is one of immersion, we must so do. But, the objectively clear example of unleavened bread and wine is to them not compelling.
There are also many who even insist that the wine used by Jesus and the disciples, and in the early church, was not alcoholic.
None of these reasons is persuasive and some are simply incredible, especially since they were unknown in the Church prior to the moralistic motivations of temperance, which, I suspect, is still at the bottom of the issue. These arguments also arise from an attitude of being fearful. It is not a muscular or manly approach to obedience to Christ and His Sacraments to fear and loath the very element that He used. It is better, to them, to offend God than to offend Man.
The Lord Jesus commanded us to observe the new covenant in His body and blood. He instituted the sacrament with unleavened bread and wine.
Who are we to change that?