This is a parable unique to Mark’s Gospel. Like the parable of the sower, it is a growth parable.
The story is about a farmer who plants seeds and can do nothing about the growth until harvest time.
This story shows that once the seed of the word of God is sown, only time will show how a person’s faith will grow and develop.
This parable shows that the Kingdom of God will continue to grow and spread until the end of time.
This parable would have offered encouragement to Christians facing persecution from the Romans. It would have reassured them that God’s reign was coming to Earth, even though it appeared to be small and sometimes invisible. It would have given them hope and encouragement that they were doing the right thing.