"I've got the guts to die. What I want to know is, have you got the guts to live?"
Big Daddy says this to his son Brick. He confronts that fact that he has cancer and he is dying all while making the attempt to get his son to stop living in the past with dead things--Skipper, his glory days as an athlete--and to be in the world with what is in front of him.
"Just staying on it I guess, long as she can."
Maggie says this to her husband Brick after he asks, "What is the victory of a cat on a hot tin roof?" Maggie is the cat and it's her simple desire to cling on to Brick as long as she can to make him love her so that she won't die poor.
"Maggie, we're through with lies and liars in this house. Lock the door."
Brick says this to Maggie after she has come upstairs after lying to his family that she is pregnant with his child. His statement declares that he will no longer be a liar and that he is going to change and the first step is making love to his wife and creating life with her.