My mom introduced me to the action of yeast the first time she let me help her make her trademark cinnamon rolls.  She had me dissolve the yeast in warm water, and then invited me to add sugar to the solution and let it rest a few minutes.  After bubbles formed and then frothed on the surface, we added the live mixture to the flour.  Kneading that new entity—the enleavened dough—was a pleasure of touch and scent, and then came the waiting time as the lump of dough became light and springy under the influence of this dynamic yeast. I was only six or seven years old, but I was totally taken in by the process—and no bread ever tasted so good.

This kitchen biochemistry lesson stays with me as I read today’s gospel.  Imagine the simple mystery of yeast – leaven – in the pre-microscope world of Jesus.  Surely it seemed magic to them that a tiny bit – seed-sized – could produce such a multiplier effect.  In Luke’s and Matthew’s gospels Jesus portrays the energy of “the kingdom of God” using the metaphor of yeast:  even the tiniest bit of activated faith in the risen Lord transforms a soul previously mired in its own density, or a previously inert community.

But in today’s gospel from Mark, leaven has a negative connotation.  Jesus has just been confronted by a group of Pharisees “demanding a sign from heaven,” as if from thin air.  The Pharisees must have heard about his recent healings and miracles, including two instances of multiplication of loaves.  They wanted a show of that energy for themselves.  They wanted to be let in on his secret.  Jesus has stood up to them (“with a sigh that came straight from the heart”), and refused to be a token shaman, a magician-on-demand.  He refused to play by their rules, to give them the part but not the whole.

In the boat traveling away from that encounter, Jesus tells his disciples:  “Beware of the leaven of the Pharisees . . . .”  He seems weary and distracted.  He senses a real danger in the approach to him taken by the Pharisees.  Perhaps he even intuits the “multiplier effect” and the negative consequences to follow in his own life.  He recognizes the inauthentic mask of fake faith.  And it seems to pain him to the core.

God, I get the feeling you are pained to your core whenever we settle for fake faith.  The enleavening Spirit lies inert in us when we choose to make other things in life our goals and our gods.  We can prefer the part for the All.

Help us to be encountered today by the Someone who invites us into the realness of life – who wakes us up to the All in whom we live, and move, and have our being and becoming.