How is the messages which emerge in this presentation of class act to contribute to the thematic movement of the work as a whole?

Where are you?  At the beginning?  In the early part where Milton tells the reader that his purpose is "to justify the ways of God to man?"  Do you mean about understanding why Satan rebelled against God and was cast down into the place we know as Hell where he would rather rule than live in Heaven under what he believes to be servitude?