For me the most important overall message (And I say "most important," because this is Shakespeare and there are, potentially, ump-teen "overall" messages.) would have to relate to the fact that the play is a Tragedy, and as such is meant to focus on the fall of a great and noble character due to a tragic flaw.
Tragedies, while not really meant to instruct the audience, are certainly intended to show how our own human nature is our worst enemy, and the more closely we look inside our own hearts and minds for the reasons our life is as it is, the more we'll understand the world around us. And in King Lear, Lear himself, suffering from the tragic flaw of a prideful and self-righteous nature, learns to see the world through new eyes, even as he suffers the consequences of his actions in the opening Act of the play.
So, the overall message, for me, is to look beyond the surface -- the title, job, sex or rank -- of a person to see what is in their heart. To not be too quick to listen to the easy words someone might speak, but to take care to watch how they behave before judging them or their actions. One of my favorite moments on the heath, in Act IV, scene vi, is when Lear, who has alleged that he knows so much about just behaviour and right and wrong observes:
Through tatter'd clothes small vices do appear.
Robes and furr'd gowns hide all. Plate sin with gold,
And the strong lance of justice hurtless breaks.
Arm it in rags, a pigmy's straw does pierce it.
So, he understands that clothes and position, ultimately do not make the man, but that we operate in the world as if they do. Of course, since this is a Tragedy, Lear learns his lesson too late. However, the audience does get the satisfaction of his reconciliation with Cordelia, once he can see her for who she really is, even though this redemptive moment cannot save either one of their lives.
the moral lessons in king lear :
- don't believe all the promises or words said by others unless they do a real thing (deed) to prove it .
- never decide to do something if you are not sure that its results will be good or useful for you and the others.
- you cannot escape your fate .
king lear destroyed his three daughters , him-self and prevented himself from being respected because of his mad decision,,,, he didn't consider the matters well enough or give himself a chance to remember what Goneral and Regan had done before saying their sweet words in front of everyone (in order to be able to rule the country and be queens).But he immediately forgot Cordelia's good deeds and manners when she said that she didn't love him more than her duty(means she loves him as he was her father who used to teach her ,bring her up & love her).
So ''actions speak louder than words'' always remember that sentence and never decide to do something without thinking.