The kingdom of heaven is like unto leaven, which a woman took, and hid in three measures of meal, till the whole was leavened. Matt. 13:33.

Leaven as used in Scripture can he either good or bad. Either the gospel or sin in the life leavens the whole person one way or another. Christ warned His disciples against the leaven of the Pharisees. This would affect adversely their entire lives.

Leaven and yeast are almost the same thing. If you use bad or poor yeast the bread will be heavy and undesirable for eating. When yeast is mixed in the dough it works its way through every part of it to make bread. So the gospel must enter our hearts and work through the whole range of our lives, in church and out of church, at home and abroad, in business and in pleasure.

We must not stop short of this. Christ did not cast only six devils out of Mary and leave one. When He exercised His power to work miracles, He did not partially heal the blind or partly cure the man at the pool of Bethesda. He made them completely whole. There is no such thing as being half leavened, with half our life given to the church and half to the world.

One sin can leaven the whole life, also. We do our best to protect our homes from fire and storm. Yet they are liable to other perils such as dry rot and termites. The tissue of the wood silently deteriorates. Our lives are liable to a similar danger. Spiritual peril does not always arise from enemies without. Not only do thieves break through and steal but moths and rust also destroy.

Some of our most serious problems emerge from within. Some sin eats away the fiber of the will, the conscience, the spiritual sensitivity. We can tolerate certain sins, cater to them, until one day a sudden temptation presents itself. We fall. Our moral and spiritual life has deteriorated. The little rift in the lute slowly widening stills the music. Worship is not abandoned. It just becomes routine. Prayer is not repudiated, only reduced. The Bible is not rejected, only ignored.

The leaven of Christ in us means loftiness of life, beauty of character, thoroughness of devotion, constant obedience to the will of God.