Why the Parables? (2) (Mark 4:21-34)

The parables are stories that can be difficult to grasp.  You can discern their challenge when you read commentaries and how people analyze all the different parts of the parables with differing opinions.  What can we take from the parables that is truly edify?  What is the clear message of the parables as we consider their message? How do the parables serve to cut us to the heart when we wrestle with the implications of the gospel?