Looking out for leaven

Today's Gospel has an interesting sort of correlation both with the feast of Our Lady of Fatima and with the message of Pope Benedict's visit here just a few weeks ago. In the Gospel, shortly after multiplying loaves to feed hungry (and immense) crowds, Jesus warned his disciples about "the yeast" of the Pharisees and of Herod. Two different kinds, evidently. Of course, the word "yeast" (or "leaven") made the hungry disciples think about the bread they did not have in the boat with them. This did not go over well with Jesus. But what was he getting at?
I remember the "friendship bread" craze years ago. You needed the "starter" in order to make a delightful coffee cake. Butyou never knew when that bubbling beige mass was going to end up bursting out of its zip-locked prison. There is a good "ferment" we need for the spread of the Gospel. It is the leaven of the Holy Spirit. Pope Benedict (speaking to the US bishops) connected the leaven that is effective Christian mission to the "state of the family in society" and activities "in harmony with the Church's teachings on today's key ethical questions."
But leaven/yeast/fermenting can also lead to a kind of infective influence. Perhaps the "leaven" of the Pharisees was religious observance turned inward, corrupted and corrupting: religious observance for its own sake. The leaven of Herod was something else again: this could be thoughtless identification with power and pleasure. In either case, a means has been turned into an end, and the true "end" has been lost from view. Pope Benedict also warned us in particular about these two leavens in society. Here in the US, we are particularly vulnerable to a religious devotion that is allowed to flourish as long as it doesn't interfere with consumer interests or impose its values on the wider world. But "imposing on the wider world" is exactly what leaven does!
The disciples with Jesus did not see or understand what Jesus was doing and what it meant, but those three children at Fatima did see and hear and understand, and they remained uncorrupted by the Pharisees' leaven of sterile religiosity and Herod's leaven of self-adoration. They brought their message to the world and declared it not just with verbal boldness, but at the cost of personal sacrifice that would be impressive in an adult. And so, almost 100 years later, their message still comes to us with the kind of power that can leaven our world.