The Law and the Gospel

Why do people divide on what we do with the law? What is it to be double-minded? Do the children of God have to do anything to obtain or maintain salvation? What is the worst condemnation? Did the Pharisees keep the law to perfection? Did they think they kept the law perfectly? Did they think themselves righteous by their own doing? How are we all like the Pharisees by nature? How was Adam unstable? Why do people bring up their law-keeping even though God said the law should shut their mouths? How are our thoughts subject to the law? Is the basis of the law love?