I am not one to engage in debates or arguments, people believe what they believe and I find little value in prying what they hold on so dearly to from there grasps. But you ask a question, so I will do my best to answear it in Faith and with Prayer. I have always been of the leaning that as Satan was numbered as part of the Sons of God in the book of Job, I have always thought just that of him, a Son of God like Christ. Now where they differ is that Christ accepted the call to be human and to sacrifice Himself for the Love of Gods creation. I would venture the thought that like many of the sibling relationships throughout the Bible,  it in many ways might reflect the dynamics of the relationship between Jesus and Satan. The child who is welling to do the Will and bidding of the Parent and the other who chooses to not!