When to Bring Yeast to a Party

Leaven is an interesting and important word in the Bible. It refers not just to yeast, as the NIV translates the word in all but one verse (Amos 4:5), but it is actually a chunk of dough that has begun the fermentation process. It would be somewhat like the 'starter' that many women swap these days to make friendship bread or other similar treats.

This leaven-lump has some very infectious properties. If a hunk of leavened dough is kneaded into an unleavened lump, it will quickly infect the whole batch of dough. This infectiousness of leaven provides two main symbolic meanings in Scripture and each of them is associated with its own Old Testament celebration.

The first - and most obvious - festival related to leaven was the Feast of Unleavened Bread which accompanied the Passover celebration. During this time, Jews were to remove all leaven from all of their properties throughout their land. This was to remind them - in part - of their quick flight from Egypt during the Exodus, which meant that they did not have time to allow their bread to rise. But, in this case leaven also symbolized the corrupting influence of evil in the midst of the people of God. They were to be consecrated to the Lord, and the removal of the infectious leaven illustrated their need to 'make no provision for the flesh', as Paul would later write in Romans 13:14. Jesus and Paul both make it clear that leaven is a symbol for the corrupting influence of bad doctrine and sinful attitudes (Matthew 16:5-12, 1 Corinthians 5:6-13).

But leaven does not always symbolize the corrupting presence of evil. If we believe that it does, then we will grossly misunderstand Jesus' parable of the leaven working through the lump of dough in Matthew 13:33. In that passage, Jesus says that the Kingdom of Heaven is like a little leaven that a woman hid in three measures of flour until it was all leavened. If we are ignorant of the fact that leaven can be a symbol of a good infectious influence as well, then this parable would mean that the church will be overrun with evil. Rather, we can see how similar this parable is to the parable of the mustard seed directly before it and understand that Jesus is talking about the spread of the gospel around the world from humble roots.

What fascinates me about this concept of leaven is that it is associated with an Old Testament celebration as well: the Feast of Weeks, or Pentecost. During this festival, which was to celebrate the firstfruits of harvest, worshippers were to bring cakes that were leavened and wave them as an offering before the Lord. It cannot then be missed that the humble roots of the Kingdom of God first began to spread the infectious gospel of the Lord Jesus Christ at exactly this time in Acts chapter 2. At that time - Pentecost - the small group of disciples began to tuck the leaven of the gospel into the dough of the world and reaped a firstfruits of 3000 in one day!

What should this teach us? I believe that we should learn to be wary of the corrupting influences of some things in our lives and remove them from our presence as far as we can, but we also need to recognize the inherent power of the gospel and its tendency to infect others. We do not wield a limp sword when we carry the word of God in our hands and in our hearts and minds. We wield the very power of God which will not return void. Just try to knead the leaven of the gospel into your conversations and watch how God works. It's quite catchy!