Our congregation uses ordinary bread (very likely leavened) for Lord's Supper. The minister, after admitting that unleavened bread was used during the Passover meal when Jesus instituted the Lord's Supper, tried to justify the use of ordinary bread this way:
1. The elements of the Lord’s Supper are the bread and fruit of the vine (Matthew 26:26-29). The Bible abounds with teachings on the significance of these two objects but makes no specification to the kind of bread (leaven or unleavened) nor to the container (one cup or many).
2. In facts, reading from the context, we are convinced that the early Christians used the ordinary bread rather than the unleavened bread when partaking the Lord’s Supper. For example in I Corinthians 11:20-22, Paul makes reference to the abuse of the Lord’s Supper carried to the point of indulgence. This seems to suggest ordinary bread (as those used in their ‘agape feasts’,) rather than unleavened bread.
3. Church history records that ordinary bread was used by the early church for the first 800 years. The Roman Catholic church then introduced unleaven bread for the Lord’s Supper to enforced their doctrine of "transubstan- tiation". Thus, they changed the Lord’s Supper into a mystic ritual, teaching that the bread and wine are trans- formed into the actual body and blood of Christ.
Paul drew a parallel between the spread of sin and the partaking of the Lord's Supper. "Therefore purge out the old leaven, that you may be a new lump, since you truly are unleavened. For indeed Christ, our Passover, was sacrificed for us. Therefore let us keep the feast, not with old leaven, nor with the leaven of malice and wickedness, but with the unleavened bread of sincerity and truth" (I Corinthians 5:7-8).
The Corinthians refused to reject a brother in their midst who was committing fornication. Their arrogance was preventing them from realizing that sin doesn’t go away on its own. It spreads secretly and rapidly, like yeast in a lump of dough (Galatians 5:9; I Corinthians 15:33; II Timothy 2:17). The only solution is to remove the cause of leavening – the one who is sinning, along with the sins they were committing – so that what remains will be without sin. Christians are to stay away from sin (Romans 6:1-2) as followers of Jesus.
Jesus sacrificed himself to save lives (John 1:29), just as the Passover lamb was killed to save the firstborn from God’s wrath. The Passover celebration took place during a week long feast when no food was cooked with leavening (Exodus 12:15; Deuteronomy 16:3-4). It was done to remember that the Israelites left Egypt in a rush and did not have time to let their bread rise. But Paul uses it to draw a greater analogy: The one who was without sin died to save us from sin.
It is because of this symbolism that the bread in the Lord’s Supper is made without leavening. Leavening represented sin. The bread in the Lord's Supper represents the body of Christ who was without sin. By keeping ourselves pure from sin we are able to keep the Lord’s Supper with an attitude of sincerity and truth. This is in contrast to the when false teachers are in a congregation’s midst and stated in II Peter 2:13-14 and Jude 12.
Therefore, your preacher ignored the fact that the type of bread was mentioned. He is also wrong the the number of cups was not mentioned. Luke 22:17 states that there many containers because the cup was divided among the disciples before it was drunk.
This man also claims that the "love feasts," a phrase that only appears in Jude 12, is a reference to common meals. Yet this claim is made without scriptural evidence. See What is a "love feast?" for details.
The second argument is that the abuse of the Lord's Supper mentioned in I Corinthians 11 was the turning of the Lord's Supper into a common meal and common meals have leavened bread. There a simple falsehood here. The common meals served during the week of the Feast of Unleavened Bread clearly used unleavened bread. Therefore, common meals can feature unleavened bread as a part of the menu.
He missed Paul's point in I Corinthians 11:20-22. Paul previously touched on the point that a core element of the Lord’s Supper was the sharing of the body and blood of Christ (I Corinthians 10:16-17). The Corinthians were not waiting for each other when partaking. Thus, when they assembled, one partakes before others arrive. Some have not partaken (are hungry) while others have partaken (are drunk or satisfied).
Note that the word “drunk” does not imply that Christians were getting drunk during the worship. Such would be a sin in itself (I Corinthians 6:9-10) that the Corinthians knew was wrong (I Corinthians 6:11). The word methuo means “filled to the full.” When used in regards to alcoholic beverages, it does imply drunkenness, as it does in English. But in regards to other things it means filled to the point of satisfaction. Since it is being used in contrast to hunger, it is being used in regards to satisfaction in this verse. As Johnson notes in People’s New Testament Commentary, “This last clause means that he had eaten and was satisfied.” To claim it was partaking to excess is add more than what was stated in the passage.
Paul’s point is that unity is not being demonstrated in the sharing of a meal with the Lord; instead, their disharmonious partaking demonstrates division. If they were hungry they should have eaten at home. The gathering of the church is not to provide meals, that is the function of the home. Their action shows disdain for the church and for their brethren left with nothing of which to partake. If they expected praise from Paul in this matter, they had the wrong idea.
The last claim is that leavened bread was used for the first 800 years of church history. I generally get suspicious when a claim like this is made without historical reference. The problem is that the Greek word for bread does not indicate the type of bread. It can be used for both leavened and unleavened bread. A search of ancient Christian writings found these quotes:
"Yesterday the Lamb was slain and the door-posts were anointed, and Egypt bewailed her Firstborn, and the Destroyer passed us over, and the Seal was dreadful and reverend, and we were walled in with the Precious Blood. Today we have clean escaped from Egypt and from Pharaoh; and there is none to hinder us from keeping a Feast to the Lord our God--the Feast of our Departure; or from celebrating that Feast, not in the old leaven of malice and wickedness, but in the unleavened bread of sincerity and truth, carrying with us nothing of ungodly and Egyptian leaven" [Gregory the Theologian (AD 329-389), Oration 1:3].
"This it is that rescues from the power of darkness and transfers us into the Kingdom of the Son of God. This it is that by newness of life exalts the desires of the mind and quenches the lusts of the flesh. This it is whereby the Lord's Passover is duly kept "with the unleavened bread of sincerity and truth" by the casting away of the old leaven of wickedness [1 Corinthians 5:8] and the inebriating and feeding of the new creature with the very Lord. For naught else is brought about by the partaking of the Body and Blood of Christ than that we pass into that which we then take , and both in spirit and in body carry everywhere Him, in and with Whom we were dead, buried, and rose again, as the Apostle says, For you are dead, and your life is hid with Christ in God. For when Christ, your life, shall appear, then shall you also appear with Him in glory [Colossians 3:3-4]" [Leo I of Rome (AD 400-461), Sermon 63:7].
These are not proof that unleavened bread must be used, but it does prove that the preacher's statement that unleavened bread was introduced in AD 800 is false. The truth is that a debate arose around AD 800 between the Orthodox and Roman branches of the church on the issue of whether leavened bread should be used or not. The Orthodox argument, which requires leaven bread, is weak because it claims that all use of bread that is not qualified by "unleavened" must refer to leavened bread. It is a claim that that cannot be proven or supported.