Leaven in the Kingdom of God

LUKE 13
20 And again he said, “To what shall I compare the kingdom of God? 21 It is like leaven that a woman took and hid in three measures of flour, until it was all leavened.”

This scripture occurs while Jesus is teaching in a synagogue. A woman who has had an infirmity for 18 years was healed by Jesus. He was then criticized by the leaders of the synagogue because he healed on the sabbath. Jesus goes on to compare the Kingdom of God to a mustard seed tree -- with birds -- birds often represent spirits in the Scripture. Jesus then states a parable of a woman that mixes leaven into flour until it was all leavened. It is interesting to me how a the church or even false churches are referred to as a woman or women. Could Jesus be talking about how the religious people of his day mixed in their own teachings and thereby corrupted the the whole bread? The lesson I take from this scripture is to pray that God would help me concentrate on his Word and not be side tracked by seemingly good religious beliefs that would really leaven the Kingdom of God.