Bartolome de las Casas viewed the natives as God's people who defended their rights against the Spanish government. He viewed the enslavement and slaughter of the natives not only a crime but also as a mortal sin as defined by the Catholic church.
The relationship between Spanish and the natives of Caribbean was filled with tension because the Spanish had taken control of the Caribbean land an treated the natives violently.
what will happen next is that Bartolome will try to prove that the enslavement and the harsh treatment of the natives isn't necessary and, that the natives can be controlled peacefully if given a chance.