Tracing sin back to it's origin, we know that when Adam and Eve disobeyed Gods instructions,sin was passed on through the generations to all of us.{"Through one man death entered in"}We know that Adam and Eve were deceived by the serpent{the devil}.So we see a pattern, the devil deceived Adam and Eve,who in turn gave birth to a sequence of humans,who were tainted with sin.Now in Heaven,the devil after changing , got some other angels to follow him,becoming demons{"And it{the dragon}took a third of the stars of Heaven and hurled them to Earth"So we know the devils job is to deceve. But here's the thing.The devil deceived the angels{"and war broke out in Heaven;Michael and his angels fought against the dragon and its angels"}So all deception originated with the devil. But now the question--who deceived the devil,the VERY ORIGINAL sin?There wasn't a devil to deceive the devil to turn on God.So I would have to say the devil deceived himself!!!He had delusions ,and deceived himself with them.You wouldn't think that there could be sin in Heaven, but here it is. Satan was able to have sinful ambitions in Heaven.So how sin started, and kicked off the cycle, if there was no one to deceive Satan , I would say he deceived himself.Agree?