Parable of the Mustard Seed
Jesus is basically referring to the way in which God's word can be received. That with a little bit of love and devotion, then God's love and kingdom can grow in each and every one of us.
Jesus addressed this parable to the people gathered before him. He was in a boat out on the water as he spoke and this was so that the masses of people could all see and hear him clearly from where they were standing at the lake side.
While talking of this parable, Jesus is referring to how the simplest and most pure thought of God and His Word can grow to change the life of he who hears and it. In particular, Jesus is talking about the love and harmony that one may experience so long as he provide a healthy house- being his heart and mind- for this these emotions to shine through God's Word.
Although it takes only a minute to plant the thought into one's mind and heart, it can take much more work to harvest this thought into a full and rich understanding, growing to appreciate God's kingdom and the work He has done for us.
Jesus likens the kingdom of God to a mustard seed. Jesus notes how small the mustard seed is, yet it is able to grow to be greater than all the herbs of the field. This certainly describes the nature of God's kingdom. It would start off very small, with only twelve ordinary men who would fail from time to time, to Jesus' resurrection appearance to the 500, to the thirty thousand that would be converted in Jerusalem on the day of Pentecost. We know that the word of God would spread from Jerusalem,