Luke 13:18-21 :
He said, “What is the Kingdom of God like? To what shall I compare it? It is like a grain of mustard seed, which a man took, and put in his own garden. It grew, and became a large tree, and the birds of the sky lodged in its branches.”
Again he said, “To what shall I compare the Kingdom of God? It is like yeast, which a woman took and hid in three measures of flour, until it was all leavened.”
The Kingdom that Jesus brought had humble beginnings. Jesus lived in a small place in a small country. He didn’t write any books or do global travel yet, somehow, His influence has spread throughout the world to the point where rules are made to separate church and state. In a very real way, the Kingdom of God started humbly and has become ridiculously enormous on earth. The parable of the mustard seed describes this. A small little seed that would normally grow up into a bush, becomes a tree! Not only that, Jesus tells us that “birds of the sky lodged in its branches.”
Birds are not usually a good symbol in Jewish stories because birds are “unclean” animals. In Jesus’ stories, birds are usually a satanic influence. I believe that Jesus was making a comment about how the Kingdom would get so large that evil would be attracted to live in it too. Christianity has certainly seen this happen and in the future earthly Kingdom of the Messiah, it happens again because people still reject Jesus at the end of His 1000 year reign. God will eventually completely remove the all evil from the Kingdom at the appropriate time, however.
“Yeast” is also a negative concept in a Jewish story. It is not legal to have yeast in your bread when you celebrate the Passover. Jesus has already warned the people about the “yeast of the Pharisees.” Again, it appears that Jesus is saying that in the “Kingdom of God” evil will get in and will spread all around.
I take this as a warning. We can’t assume that just because someone is a Christian, or makes a Bible Study Blog that they are good. We need to keep our eyes out for the yeast and the birds that Jesus warned us about. We need to be careful not to be fooled. That’s why it is so important to study the Bible for yourself and to look at things that Bible teachers say and compare it to what the Bible really says. Yeast spreads and it can also corrupt someone who wasn’t corrupt at first.
There are many bad teachings that are spreading like yeast in the Church today that are more about what people want to hear than they are about what the Bible really says. It is important to be critical about “Christian teaching” because we have been warned that evil does mix itself in.