All the Bible is Scripture, but it is not all God's speaking. It includes man's thoughts, with his speaking, such as Job's friends. After all their blather, God came in and rebuked them. It also includes God's speaking. He said in Isaiah 55, My thoughts are not your thoughts, and your ways are not My ways. For as the heavens are higher than the earth, so My ways are higher than your ways, and My thoughts than your thoughts. It also includes Satan's speaking. You should differentiate who is speaking or you might end up taking death into yourself, like Adam and Eve did. Nevertheless, ALL Scripture is profitable "for reproof, for correction, and for instruction in righteousness."