5Now when His disciples had come to the other side, they had forgotten to take bread. 6Then Jesus said to them, "Take heed and beware of the leaven of the Pharisees and the Sadducees."
7And they reasoned among themselves, saying, "It is because we have taken no bread."
8But Jesus, being aware of it, said to them, "O you of little faith, why do you reason among yourselves because you have brought no bread? 9Do you not yet understand, or remember the five loaves of the five thousand and how many baskets you took up? 10Nor the seven loaves of the four thousand and how many large baskets you took up? 11How is it you do not understand that I did not speak to you concerning bread? -- but to beware of the leaven of the Pharisees and Sadducees." 12Then they understood that He did not tell them to beware of the leaven of bread, but of the doctrine of the Pharisees and Sadducees.
Beware the leaven of the Pharisees and Sadducees. Why the warning to beware? It should be pretty easy for them to understand the misdirection of the Pharisees and Sadducees doctrine after hearing Jesus preach the truth. It should be easy to not follow their doctrine. So why beware?
First of all, His disciples demonstrated the weakness of their faith. Their focus seemed to still be on their physical needs. Having access to food seems a reasonable concern for a group who keeps moving from place to place, oftentimes in open wilderness, with no set plans on how they will meet their basic physical needs. How could they forget that Jesus will feed them if they find themselves without food? He has done it more than once, with very little food and large crowds to feed. I'm not saying that we should never have arrangements for food when we travel, but that this was a weakness of their faith. Where are the weaknesses in our faith? Is our faith strong, or are we of little faith like Jesus' disciples?
Jesus says to beware of the leaven of the Pharisees and the Sadducees. Back in Matthew 13:33, Jesus said that the kingdom of heaven is like leaven, which a woman took and hid in three measures of meal till it was all leavened. After thinking about what He meant by leaven as I studied that text, I thought of several possibilities: it spreads on its own throughout whatever it is put into, we cannot confine it, and it lightens what it is put into.
The Pharisees and Sadducees asked for a sign. In some eyes this may seem like a reasonable request. But if you let some of the Pharisees and Sadducees way of thinking into your mind, it may act as leaven and spread to the rest of your faith too. As leaven it will permeate the whole. It may even seem to make your burden lighter if you consider some of their questions, but it will only draw you away from the truth. Beware.
What did Jesus do when He was met by the leaven of the Pharisees and Sadducees, when they asked for a sign from heaven? He would not let the seed of doubt get planted in those of little faith around Him. He countered their request with their inability to see the signs around them. He took His disciples away from them and warned His disciples to beware of their influence.
We need to beware too. We need to be aware of the outside influences around us. And we need to be wary that they do not influence us. For it is as leaven. Rather, let the leaven of heaven take over.