Thoughts
Christ introduced shades of grey to the Mosaic law. The Jews were very black and white. If you took more than a perscribed number of steps on the sabbath you were a sinner. Christ turned the attention not to outward actions, but to the contents of the person's heart, whichn really, is where the seed of all action resides. If you have good intent the majority of your actions will be good. If you have ill intent, if you're doing things without the good of others (and yourself) in mind your actions reflect that as well. By their fruits ye shall know them.