To what shall we compare the Kingdom of God? "The Kingdom of God" is a concept that was not alien to the majority of those who were listening to Jesus. The sons and daughters of Israel who constituted the larger portion of Jesus’ audience understood themselves as belonging to the kingdom of God. They “owned” the kingdom. To them, their nation (land) and the kingdom of God were synonymous and could be used interchangeably. Had the Lord not chosen them from among the nations and made them his? Had the Lord not made Israel God's first born? It was a privilege in which they took pride, and rightly so, because belonging to the Lord is an honor with no parallels. Jesus himself perfectly understood this, and in many of his parables about the kingdom of God, his main objective was not to dispute this understanding or to belittle Israel’s pride. He only intended to give it a new interpretation that was not only commensurate with their time but one which could fully bring out its meaning and implication. 
Because of the then prevalent understanding that one was "born into" the kingdom, the kingdom as a concept remained very passive and inert. It must have even been taken for granted by those who took pride in it. One did not have to struggle or do anything special in order to belong to the kingdom. Since belonging to the kingdom, as it were, was assured, the “citizens” of the kingdom lost interest in what the kingdom was about. This is why when Jesus emerged into the scene, he preached the in-breaking of the kingdom, that is, the coming “out of the shadows” of the kingdom. The parables that he uses in today’s reading to describe the kingdom portrays a kingdom that is engaged, a kingdom that is active, a kingdom that is alive. Just as a seed that is planted must grow because of coming into contact with the moist soil, so is the seed of the kingdom planted in the hearts of men and women. The kingdom must grow inside of men and women, and that growth must be felt by others. For it is only when the effect of the kingdom is felt by those who “do not belong” to it that the kingdom can be said to be growing. 
As those who have set their feet into the kingdom by virtue of our baptism, may we join Jesus in bringing from the shadows the concept of the kingdom. May we transform the kingdom from a mere passive concept to an active reign of God. May we use our privileged citizenship to extend the borders of the kingdom of God to include every man and woman. May all creatures of the Lord find rest and life in the kingdom of God which we proclaim.