Some people say that in order to get to Heaven, you have to believe certain things. For example, you have to believe God exists, that Jesus is his son, etc. The Devil knows first hand that God exists, that Jesus is his son. Therefore, the Devil passes the tests. We know the Devil has certain, albeit limited, supernatural powers. For example, in the Bible, the Devil takes Jesus up a high mountain/building. He offers Jesus anything he can see, if Jesus will worship him. How could he do that to the Son of God / God ? In the book of Job, God allows the Devil to torment Job. According to another book, the Devil tempts king David to conduct a census. What is the source of the Devil's power ? Also, the Devil must be really dumb. He knows exactly what is going to happen to him if he doesn't repent. But he won't (according to Revelation).