'Good for nothing' in the Bible

"You are the salt of the earth, but if the salt has lost its flavor, with what will it be salted? It is then good for nothing, but to be cast out and trodden under the feet of men.

But I tell you, that everyone who is angry with his brother shall be in danger of the judgment; and whoever shall say to his brother, 'You good-for-nothing.' shall be in danger of the council; and whoever shall say, 'You fool.' shall be in danger of the fire of hell.