At the end of this parable Jesus states that "to those who have, more will be given and to those who have not what little they have will be taken away."
As I understand this is that when a person has a state of ming of gratitude to the Creator and feels abundant God provides more of the same. When we feel wronged by God and ungrateful for the little He has given we naturally repel any good that can come our way.
This parable is Jesus explaining the natural laws of the Universe, The Laws of God.
To those who have more shall be given, to those ungrateful people who bemoan there lot will have what little they think they have taken away.
Try it. It works.
Read Mind Power by John KEHOE - he explains this parable very well.
Thankyou have a good day.