Among the Holy Days of Leviticus 23, God commanded Israel to celebrate the Feast of Unleavened Bread every year. They were specifically commanded to remove the yeast from their homes for 7 days and to not eat anything leavened with yeast for those 7 days. This yearly festival was primarily a commemoration of the Exodus, and specifically of the fact that God brought Israel out of Egypt by His power:
Exodus 13:3-8
And Moses said to the people: “Remember this day in which you went out of Egypt, out of the house of bondage; for by strength of hand the LORD brought you out of this place. No leavened bread shall be eaten... And you shall tell your son in that day, saying, ‘This is done because of what the LORD did for me when I came up from Egypt.’"
God devastated and overcame the power of the Egyptians with the plague of the firstborn (the
Passover plague) and then led Israel out of Egypt on the day after Passover, which is the first day of the Feast of Unleavened Bread. As a matter of fact, the first words that Moses and Aaron spoke to Pharaoh were about this Feast:
Exodus 5:1
Moses and Aaron went in and told Pharaoh, “Thus says the LORD God of Israel: ‘Let My people go, that they may hold a feast to Me in the wilderness.’”
The Feast of Unleavened Bread clearly focuses on deliverance - so what point is God trying to make by asking us to not eat leaven during these days?
First, recall that Israel was commanded to leave Egypt
in haste - they couldn't delay their leaving in order to give the bread time to rise, so God told them not to put any yeast in it. Yeast is a living organism that grows in bread and releases gas, which cases the bread to puff up over time as the yeast grows and spreads. They were supposed to be
eager to get out of Egypt! The deliverance symbolism of the Feast is obviously made manifest because of God's act of deliverance, but the Israelites were to commemorate the event by eating unleavened bread in order to symbolize their willingness and readiness to receive that deliverance.
The Israelites had a problem with not trusting God to provide for them, and, as a result, they frequently wanted to go back to slavery in Egypt. In light of what the unleavened bread was supposed to mean for them, it's not surprising that the one of the fond memories that the Israelites had about Egypt was the bread that they ate there:
Exodus 16:3
And the children of Israel said to them, "Oh, that we had died by the hand of the LORD in the land of Egypt, when we sat by the pots of meat and when we ate bread to the full!"
The Israelites were so unappreciative of God's deliverance that they were not satisfied with the unleavened bread which symbolized that deliverance - they wanted to return to Egypt, where they ate leavened bread in bondage!
All of these things are written for our learning. Today, Christians are
still commanded to eat only unleavened bread for 7 days. We observe the Days of Unleavened Bread to commemorate that God has
Passed Over our sins and
redeemed us from slavery in spiritual Egypt, which is the way that leads to
death. The reason that we eat unleavened bread is to remind us of the urgency with which we are called to stop living under the control of sin. Just like the Israelites were not permitted to wait around in Egypt for the bread to rise, so also Christians are not permitted to continue in their sins. The New Testament teaches that sin is like yeast:
1 Corinthians 5:6-8
Your glorying is not good. Do you not know that a little leaven leavens the whole lump? 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.
Just like yeast lives in the bread, spreading and growing until the entire loaf is puffed up, so also sin lives in us, spreading and growing until we are thoroughly captive to it. If we delay in purging out our sins, they will spread like leaven in our lives until they completely control our us. Therefore, we must not compromise! When God reveals to you that you are doing something wrong, you must be READY and WILLING to change!
We are called to eat the "unleavened bread of sincerity and truth." If you are not ready to stop sinning, then you are not sincere. If you say that you are ready to stop sinning but you willingly going back for "one last fix," then you are a liar and have not abided in truth.
The primary message of the Days of Unleavened Bread of Christians is that God has brought us out of sin by His power, which is displayed in the Passover sacrifice. As a result of that deliverance, we must be totally ready to accept our salvation by willingly and eagerly following God out of sin, symbolized by eating unleavened bread - putting away sin before it has a chance to grow and corrupt us.