When we celebrate a major Christian holiday, the center-piece of the banquet table is (traditionally) a large, roasted hunk of meat. It represents security (providence) and celebrating by splurging (killing the fatted calf, so to speak).
But, in the most celebrated Jewish holiday, the big one, that even the not very Jewish, Jewish people celebrate, while there is certainly an abundance of protein, the center-piece of the banquet table is a tray of crackers.
The Feast of Passover also begins a seven day period of worship called the Festival of Unleavened Bread. During this time, or during the week leading up to Passover, all the leavening agents and leavened food (yeast and other fermenting agents that will cause bread to rise) are removed from the home: disowned, destroyed or sold.
For a week, the family commits to not eating anything with yeast in it. And so, these crackers, called matzah, become a central part of every meal.
So, what's the big deal about leaven?
Leaven is actually good for you. There are enzymes in yeast breads that really help your body digest food properly. Without it, many people suffer from a number of physical ailments. On every Sabbath day of the year except the week of Unleavened Bread, Jewish people celebrate with a fat, yeast-filled loaf of bread called "challah". But, like anything else, there is a such thing as too much of good thing. And many doctors have concluded (okay, probably Jewish doctors) that taking a break from it for a week can be really beneficial.
But, since this is commanded by God as one of the highest celebrations of the biblical calendar, it's probably safe to conclude that this practice is not just about roto-rootering the ol' intestinal tract. There's something spiritual going on here. And, since it was so implicitly commanded by our Lord, and so carefully practiced by our Messiah, we may assume that it is something of tremendous value to us.
Yeast is actually a fungus that lives in the air. Jewish Orthodoxy has figured out that, from the time you mix water with flour, you've got 20 minutes to get your bread baked before the yeast micro-organisms can infest your dough. Matzah that is "Kosher for Passover" has been overseen by professional watchers who guarantee that the bread making process has been properly (and speedily) executed.
But, if yeast is really such a good thing, and really a celebrated part of Hebrew worship 51 weeks out of the year, why is it so very important that we remove it utterly from our lives on Passover?
Our Messiah answers this question in Luke 12:1. He says to His disciples, "Beware the leaven of the Pharisees, which is hypocrisy."
Now, in our Greek New Testament, the Greek idea of hypocrisy means duplicity: or, saying one thing and doing another. And while there is pretty solid evidence that this characterized the behavior that Messiah was talking about, there's no Hebrew word that specifically represents hypocrisy. If he were speaking in Hebrew or Aramaic, He would have most likely used the word "khan-aife" which simply means dirty, soiled or unserviceable.
Here's what my mom used to tell me about being dirty, or wearing dirty clothes. It gets the furniture dirty and unserviceable. It makes your food taste bad, and can sometimes make you sick. It causes your friends (who are not dirty) uncomfortable to be around you. And while being dirty is a regular, necessary, and often fun part of life, there are times that it is important to be not dirty.
Being dirty (of khan-aife) is, really, by the simplest definition, hypocrisy. It is including something foreign to the pure substance of something. It makes your potato salad unreasonably gritty. It changes the patterns floral patterns on the couch. It causes people to see something on you/in you other than what is really you.
The Passover celebration represents our deliverance by God from the evils of this world. It was His rescue mission, to take us out of a life characterized by bondage and oppression. But, such a mission would be utter failure, unless we could be able to see ourselves, and each other, as we really are; not characterized by the duplicity, the forces that suppressed our true character, in our precious life. Unless we can shed ourselves of the leaven in our lives, the exterior circumstances that define us, we can never really see and understand who it is (what we are) that God sees and saw worthy of saving.
This is what the Festival of Unleavened Bread is all about. Starting the week before Passover, we begin the search to remove all the things that limit who we are, that define us by what they have done (or are doing to us). We want to meet with God, on Passover, as unleavened, without hypocrisy, without duplicity, or circumstantial definition. This doesn't happen by flipping a switch, or taking a bath, of making a decision. It is a process of worship, finding pockets of spiritual and emotional fermentation that we may not have even realized was there. And while, whatever it is, can't help but have an impact on who we are, we can recognize it and put it away, just for the celebration of Passover.
At Passover, we declare with a shout, "Once we were slaves, but now we are free!" Without taking the time to remove the leaven from our lives, we can really never understand and appreciate what that means.