Jesus told this parable against those people who think that God has only an interest in one tribe, one nation or one group of people. Jesus wished to show that God has no favourites. He may have chosen Israel  to be an example of his love they were the light bearers. This is a story picking up the theme of the first parable when looked at.  Israel believed that  God would break into time and renew his creation. They often used the metaphor of a banquet to describe the coming Kingdom. This parable illustrates the refusal of the Jewish community to recognise Jesus as Messiah and it also highlights the idea that God is the God of all the nations. The gospel of Jesus is for all who will receive the invitation.