In Matthew 13:10-11 it says, "And the disciples came and said to Him, (Jesus) "Why do You speak to them (the crowds of people) in parables?" 11 Jesus answered and said to them, "Because it has been given to you to know the mysteries of the kingdom of heaven, but to them it has not been given.  What are the Mysteries of the Kingdom of Heaven and how do they affect and impact our relationship with God and Christ?