For we wrestle not against flesh and blood, but against principalities, against powers ... against spiritual wickedness in high places. —Ephesians 6:12, KJV
Satan already knows his doom, and he is also aware that his time is limited.
Something else that is certain about Satan is that he will try to take everybody down with him. He tries to do this by keeping people from being saved. He is called "the god of this world" who blinds "the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them" (2 Cor. 4:4, KJV).
When Satan fails and people are converted, he then does all that he can to keep them from holiness. He will try to get them to grieve and quench the Spirit.
New Christians need to be taught these things. They also need to know the devil will attempt to push us to extreme views about him. He will either try to get us to be overly preoccupied with him or to disregard him completely. If we become preoccupied with the occult, even if it's on the grounds that we just want to learn more about the dangers of Satan, we open ourselves up to oppression, if not possession, by evil spirits. So we need to be very careful. At the other extreme, if Satan can get us to discount anything to do with the occult as foolishness, he will be very pleased because then we will fail to be on our guard.
Here are nine more things about the devil: he is jealous, insecure, vengeful, and persistent. He is also unteachable (he never learns from his mistakes), a liar and a deceiver, and he is full of hate. But, most of all, he is resistible.
"Resist the devil, and he will flee from you" (James 4:7). That is a promise, and it works!
Excerpted from Worshipping God (Hodder & Stoughton, 2004).