What is the significance in Oedipus the King?What are the significant themes or ideas in the play?

One of the most profound characters in all of literature, the evolution of Oedipus' character is probably one of the most significant aspects of the drama.  His evolution in character from who he is at the start of the play to who he is at the end of it reflects much of the essence of dramatic depictions of character development and evolution.  His intelligence and faith in his own sense of self as well as his immense sense of pride give way to a different understanding of self.  The sight he gains about his condition in the world is only heightened by his blinding at the end of it.  Through Oedipus, we learn the truth behind the idea of knowledge being a form of suffering and the blissful condition of ignorance.  Oedipus demonstrates how the quest for truth is a necessary part of the human condition, and in the process how its suffering causes inevitable hardship and emotional turmoil.  Another significant element in the drama is the idea of human freedom vs. fated destiny.  When Oedipus seeks to overcome the fate that has been destined for him, we see a fundamental theme that underscores so much of literature.  How does human freedom fit within a cosmic design?  Are our actions in accordance to our own will or some larger scheme of which we are a small part?  If there is a destiny, can we overcome it? If this is true, is there such a thing as freedom within the human condition or is everything predestined?  What becomes the purpose of possessing freedom if destiny will triumph over it in the end?  These questions all strike at the heart of Sophocles' work, making it extremely significant.