The Bible describes a world that is far more complex than the world we have inherited from modern, empirical science. The biblical world requires that we not only engage our reason and senses, but that our faith-filled imagination also be constantly engaged in order to understand fully the world around us. Indeed, the Bible posits a world that contains beings that elude our ability to identify them 'empirically'. We 'sense' them, we experience their presence or their activity, but not usually in any scientifically quantifiable way. We simply know we have experienced something; pleasant or unpleasant. The Bible calls these beings, 'spiritual' beings', and they inhabit the same world you and I inhabit, yet their existence involves another aspect; one which eludes the modern, mostly 'faithless' world. We experience these beings but they elude our common empirical categories of description. We know them, but we can't explain them with scientific categories. Indeed, the only way these beings make sense to us, is that the Bible gives us a socio-linguistic framework by which to understand their existence.
The Bible tells the reader of the existence not only of God, but of 'angels' (from the Greek a‡ggeloß meaning, "messenger") and 'demon' (from the Greek, daimo/nion meaning,"demon"). In the scriptural narrative, the angels are messengers from God and serve God with absolute loyalty. We see this in the Old Testament as well as the New, from Genesis to Revelation. They are transcendent beings; beings that elude qualification in our empirical reality. They are ever present to the timeless, spiritual realm which God the Father inhabits, but also have the ability to participate in the earthly reality which human beings inhabit. They have the ability to remain hidden from human eyes, or, they can 'reveal' themselves. Likewise, the demons in the scriptural narrative are present in both the Old and New Testaments. These transcendent beings do not operate in the heavenly realm of God, but according to intratestamental or apocryphal literature - have been relegated to the earthly realm. These beings stand in opposition to the angelic beings and indeed stand in opposition to God's will on the earth. Rather than serve God, the demonic serves the former angel of the presence of God, Lucifer; also called Satan or the Devil. He is the great deceiver, the father of lies and seeks to keep humankind from attaining the eternal destiny God has chosen for them in Christ. This 'fallen' angel, according to non-canonical sources, led a rebellion of angels against God, who then banished these angels to an earthly existence, where they remain with fallen humankind until the final Judgment. While on this earth, they seek to keep humankind from obedience to God's will with the final goal of defrauding humanity of salvation and eternal life.
While demons seek to hamper God's will upon the earth and defraud humankind of salvation, Angels seek the opposite. Angels not only seek to implement God's will on the earth, but they stand ready to aid humankind in their struggle against evil and in their effort to find redemption in Christ. They respond only to the commands of God the Father.
Human beings, blissfully unaware of this battle between Angel and Demon, good and evil, tend to be pawns in this war, until they receive Christ in the process of salvation and the Holy Spirit enters their lives. At this point, everything changes.
For next time: the nature of spiritual warfare.