A Memorial for All Generations
"And this day shall be unto you for a memorial; and ye shall keep it a feast to the Lord throughout your generations; ye shall keep it a feast by an ordinance for ever." (Exodus 12:14).
Since the redemption and exodus of the Hebrews from bondage in Egypt, the people of Israel have celebrated the Passover as a memorial to God's intervention for them. For over four hundred years were the Hebrews enslaved and oppressed by the Egyptians. God came down and saw their oppression, and He remembered His covenant with Abraham, Isaac and Jacob and determined to deliver them from bondage. God raised up Moses to be the one who would lead them out of Egypt, and who would stand before Pharaoh with the decree, "Let my people go." On nine occasions, God would smite Egypt with a plague and Pharaoh would promise to let the people of Israel go, only to renege on his promise once the plague was lifted. But the tenth plague God would send upon Egypt would be the one which would break Pharaoh's spirit and force him to beg the Hebrews to leave.
Exodus 12:12 begins the account of God sending forth the death angel to destroy all of the firstborn in the land of Egypt of both man and beast. God gave specific instructions on what the Hebrew people should do to prepare for the coming of the death angel that their firstborn would be spared. Each family was to take a year-old male lamb without any spot or defect and kill it in the evening of the fourteenth day of the month Abib. Then some of the blood was to be taken and placed on the top and sides of the doorposts of the house. When the angel of death went through the land, he would pass over the homes which had the blood sprinkled upon the doorposts, sparing the Hebrews from the judgement coming upon Egypt.
For the Jewish people, the Passover celebration, or Feast of Unleavened Bread, had at it's center the commandment to abstain from bread made with yeast for seven days. God instructed Moses, "This is a day you are to commemorate; for the generations to come you shall celebrate it as a festival to the LORD-a lasting ordinance. For seven days you are to eat bread made without yeast. On the first day remove the yeast from your houses, for whoever eats anything with yeast in it from the first day through the seventh must be cut off from Israel. On the first day hold a sacred assembly, and another one on the seventh day. Do no work at all on these days, except to prepare food for everyone to eat; that is all you may do." (Exodus 12:14-16).
In the Scriptures, yeast is associated with sin and corruption, and this unleavened bread represented the separation of the redeemed Israelites from Egypt, that is, from the world and from sin. Not only was yeast not to be used in the making of bread, yeast was not even to be found within the borders of Israel (Exodus 13:7). As with sin, it doesn't take much leaven to "leaven the whole lump." Yeast, which produces fermentation, permeates the whole and is comparable to the process by which sin and wickedness can slowly spread until a whole congregation or society is corrupted.
Any person in the camp of Israel who ate yeast was to be removed. Likewise, for the Christian who lives openly in sin and refuses correction and reconciliation, the apostle Paul declared to the church at Corinth, "Don't you know that a little yeast leavens the whole batch of dough? Get rid of the old yeast, so that you may be a new unleavened batch-as you really are. For Christ, our Passover lamb, has been sacrificed. Therefore let us keep the Festival, not with the old bread leavened with malice and wickedness, but with the unleavened bread of sincerity and truth. I wrote to you in my letter not to associate with sexually immoral people-not at all meaning the people of this world who are immoral, or the greedy and swindlers, or idolaters. In that case you would have to leave this world. But now I am writing to you that you must not associate with anyone who claims to be a brother or sister but is sexually immoral or greedy, an idolater or slanderer, a drunkard or swindler. Do not even eat with such people. What business is it of mine to judge those outside the church? Are you not to judge those inside? God will judge those outside. "Expel the wicked person from among you." (1 Corinthians 5:6-13).