Video from Grace for Purpose
We live in an age of spiritual skepticism were we find it difficult to believe in, or at least take seriously, the reality of things in the unseen realm. This, as you would expect, offers convenient cover for the spiritual beings that the Bible considers our greatest enemies – demons.
Demons (Greek for Intelligent) are angels that lost their position in heaven due to sin, and were thus cast down. The Leader of the evil angels is “Satan” or the “devil.” From a corporeal sense Satan and his evil angels are “spirits” (Luke 24:39, Ephesians 6:12), therefore they are not omnipresent like God.
Satan cannot be in multiple places at once so when the Bible speaks of Satan tempting or attacking people, it means that he is working through the agency of the demons under his control. Just as there are many, many angels (Daniel 7:10), there are many demons sufficient number to accost every person in the world. Scripture also describes this large numbers of demons as though they were strategically arranged into a military system to carry out the will of the devil. The Bible uses terms such as principalities, powers (Ephesians 6:12), thrones, dominions (Colossians 1:16), princes (Daniel 10:13), gods, lords (1 Corinthians 8:5), angels (Romans 8:28), spirits (Matthew 8:16, 12:45), unclean spirits (Matthew 10:1), evil spirits (Luke 7:21), seducing spirits (1 Timothy 4:1), and elemental spirits (Galatians 4:3).
Nothing in the Bible teaches how the kingdom of the Satan is organized, but we must conclude that Satan is not merely formidable, but also very well organized. Thus, when we are told that the devil prowls around like a lion looking for whom he might devour, the agents doing the actual prowling are usually subservient demons.
How these spirit beings influence us is not exactly known yet based on what scripture tells us about Satan's attacks on Job and else where in the bible it's obvious they manipulate our environment and us as well. All of this is strictly within rules of engagement established by God the Father.