INTRO: As I have spent some time in studying the powers of darkness I have mentioned to you that I have learned how clean true Christianity is. It is clean. It is pure. I am talking about true Christianity. As I thought of that I found that demons are called unclean spirits.
Now turn with me to Matthew 10:1. It says, "And when He had called His twelve disciples to Him, He gave them power over unclean spirits, to cast them out, and to heal all kinds of sickness and all kinds of disease." Note that demons are 'unclean'. There are two kinds of angels; two kinds of spirits, clean and unclean. Note with me that the name of the Spirit of God is the "Holy Spirit". Holy is that which is clean or pure or undefiled. Satan's spirits are all unclean spirits, defiled, and unholy. The NT speaks of the holy angels. That is in contrast to demons which are unholy or unclean spirits.