What does Sophocles' Antigone communicate to the audience?

In Antigone, Sophocles communicates the importance of being humble. 

At the end of Antigone, there is a profound sense of emptiness.  We have seen Creon and Antigone collide with one another because they believed in the authenticity of their convictions.  Antigone believed she was doing right by her beliefs.  Creon is equally adamant in his unwillingness to compromise.  Family members appeal to both of them to change their mind.  However, neither one sacrifices their ego and, as a result, the unthinkable takes place.  While Creon does relent, it is too late.  The deaths of Creon's son and wife along with Antigone's death represent sadness resulting from human foolishness. 

Sophocles communicates the danger of self-aggrandizement.  He conveys the calamity that can await when we believe that we are better, smarter, and stronger than we really are.  This is revealed at the drama's conclusion. Creon appears before the Chorus and the audience as a broken man:

Let this rash man be led out of the way,
who, my child, unwillingly slew you,
and this woman, you, too—alas! I have
no where to turn to, nothing to lean on,
for everything goes cross in my hands,
and a difficult fate falls on my head.

Creon's language is very different from the bluster he displayed throughout the drama.  He has recognized that living a life without humility has made him a "rash man." He knows that his hubris resulted in the deaths of his son and wife.  He is forced to admit his limitations, a reality he would not previously entertain. Creon communicates how "a difficult fate" crushes us when we do not limit our ego and listen to others' counsel.

Sophocles communicates how we need to live within our limitations in order to find happiness.  In the drama's final lines, the Chorus communicates how we must be different than Creon or Antigone:   

Knowledge truly is by far the most important part
of happiness, but one must neglect nothing
that the gods demand.
Great words of the over-proud
balanced by great falls
taught us knowledge in our old age.

We are punished through "great falls" when we live as "the over-proud." Sophocles tells the audience that knowledge and wisdom mean living with humility and deference to something larger than ourselves.  Creon and Antigone communicate the dangers of living otherwise.