Can you imagine describing a vivid sunset to a blind man? Or a magnificent symphony to a deaf woman? I believe Jesus faced a similar dilemma when He endeavored to instruct us about the kingdom of heaven.
How do you go about illustrating something to someone without a shared frame of reference? Jesus knew if there was any way we were ever going to understand what His kingdom was like it would be through the use of parables.
The definition of a parable as "an earthly story with a heavenly meaning" has often been mocked but rarely improved upon. Jesus employed familiar objects and relationships and settings in order to teach His audience what He wanted them to know. Even more, Jesus often chose timeless elements which speak to people everywhere, regardless of culture or background. That is why they are still relevant and powerful today, 2000 years later.
The parables of Matthew 13 are "wild" in that they are natural and earthy. Many of them have to do with agriculture. Others with buying and selling. They are images we can relate to, and they contain lessons we can learn from.
Thus the parable of the sower (vs. 3-9) is about how you can get different results, or yields, from your efforts, depending upon the type of ground that receives your seed. It's an earthly story, but the heavenly meaning comes when we apply it to our evangelistic efforts (vs. 18-23).
Likewise, the parable of the weeds among the wheat shows us that good and evil co-exist in this world, intertwined and commingled until the coming day of judgment sorts it all out.
The parable of the mustard seed illustrates that incredibly large and influential things can come from very small and humble beginnings. As we might say today, great things come in small packages!
The parable of the yeast demonstrates the pervasive power of the kingdom, affecting everything around it so that it spreads very naturally, like the way yeast works through dough.
Like a buried treasure, the kingdom of heaven is worth everything to the one who finds it.
Like an investment worth more than anything else - such as a perfect pearl - the kingdom of heaven is worth everything you can give to it, or for it.
The parable of the net, like the parable of the weeds sown among the wheat, reveal that good and bad both exist together in this world, until the time of sorting.
Finally, Jesus points out that the disciples, too, have the power to share deeper meaning through commonplace objects in His parable of the master of the household who brings forth both new and old out of his treasure.
The kingdom of heaven may not be able to be grasped by our minds other than through these elusive glimpses of the parables.