Parables give us the best chance of seeing, hearing and understanding spiritual truths and the parable of the sower is no exception. The problem is with us; with our dull hearts, our stopped ears, our closed eyes, and our innate spiritual unconsciousness.
Each individual is represented by one of the 4 different soil types referenced in this parable. As Christians we should desire with all our heart to be the good, fruitful, soil.