Words and heart

Matthew 12:34-37
[34]You snakes — how can you say good things when you are evil? For the mouth speaks what the heart is full of.
[35]A good person brings good things out of a treasure of good things; a bad person brings bad things out of a treasure of bad things.
[36]“You can be sure that on Judgement Day everyone will have to give account of every useless word he has ever spoken.
[37]Your words will be used to judge you — to declare you either innocent or guilty.”