~Spurgeon, "A Fragment Upon The Downgrade Controversy"
Remember, Jesus said to beware of the leaven of Herod and the Pharisees; Paul said that a "little" leaven leavens the whole loaf.
Mar 8:15 And He was giving orders to them, saying, "Watch out! Beware of the leaven of the Pharisees and the leaven of Herod."
1Co 5:6 Your boasting is not good. Do you not know that a little leaven leavens the whole lump of dough? 1Co 5:7 Clean out the old leaven so that you may be a new lump, just as you are in fact unleavened. For Christ our Passover also has been sacrificed.