She agreed to help him 'out of the goodness of her heart'. [=because she is a kind and generous person]
He finally got a raise. 'Goodness knows' he deserved one. [=he certainly deserved one]
If you cook the vegetables too long, they'll lose all their (natural) 'goodness'.
(..) What good timing. We've got another guest. - Will you let him in? - Sure. Haku! Haku. Thank goodness. You're alive! I can't believe it. How did it happen? That's love for you. Look, Granny. (..)2001 Spirited Away
(..) It's called "love." - He just keeps getting bigger! - I'm scared. - I don't wanna be eaten by it. - It's her. Oh, Sen, thank goodness. Yubaba can't hold him off much longer. There's no need to get upset. I'm sure they'll fiind Sen somewhere. Where is Sen? I want Sen! (..)2001 Spirited Away