Leaven

 
Leaven in scripture is always a symbol of evil, and often of evil doctrine as well; e.g. “beware of the leaven of the Pharisees and of the Sadducees” (Matt. 16:6). As in physical baking, leaven is characterized by its infesting and spreading character. Yeast works in this way to create evenly spaced bubbles in bread. The Church is warned twice that evil must be judged, or the whole will be corrupted; in 1 Cor. 5:6 it is in connection with moral evil, and in Gal. 5:9 in connection with doctrinal evil. 
 
Six types of leaven. There are a number of different “leavens” that are mentioned in scripture.
 
Three have to do with moral issues:
  1. The “leaven of the Pharisees is hypocrisy (Matt. 16:5-12; Mark 8:15; Luke 12:1)
  2. The “leaven of the Herodians is worldliness (Mark 8:15)
  3. The leaven of the Corinthians is immorality (1 Cor. 5:6-8)

Three have to do with doctrinal issues:

  1. The “leaven of the Sadducees is skepticism (Matt. 16:5-12)
  2. The leaven of the Galatians is legalism (Gal. 5:9)
  3. The leaven of the Kingdom is evil doctrine officially taught by the Church (Matt. 13:33)

References:

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