The Scriptures are abundantly clear that human beings are not alone in the universe. The stars are inhabited by an innumerable company of angels and demons (Eph_1:21; Eph_3:10; Eph_6:12). The earth as well serves not only as home to the people of every nation and language, but it is also the sphere in which Satan and his angels (Rev_12:9) seek to imitate God, oppose His purposes, and corrupt the children of men as much as their depraved powers are able to do.
The study of the person, power and plan of Satan should be undertaken with the utmost seriousness by every child of God. He is our enemy and constantly seeks to thwart the plan of God in our lives and cause us to live and die defeated in our service to God and in the process of sanctification. There is a sin unto death (1Jn_5:16 b) and Satan would have every Christian commit it. What is this most evil of sins? Rom_8:13 tells us that “if ye live after the flesh, ye shall die.” Living after the dictates of our own hearts, living to fulfill our own wants and desires, rather than living for and loving our Creator and submissively following Him is the great temptation of the child of God. May we not be ignorant concerning Satan and may he never get an advantage over us.
[This] subject is vital to any right understanding of the age in which we live, and of the personal conflict which we wage; for the existence, personality, and power of Satan are awful facts and of immense present significance. We walk in the midst of his snares, hear on every hand his doctrines proclaimed by men of blameless lives “transformed as the ministers of righteousness,” and are allured by the pleasure, place and power of his perfectly organized world-system. (C. I. Scofield in the Forward of Satan, by Lewis Sperry Chafer)
In light of the prophesied onslaught of deceiving spirits against the Church in the last days (1Ti_4:1-3), so apparent in its incipient fulfillment now, the unbelief of Christian people is all the more tragic as many believers suffer demonic deception and despoliation [damage] because of sheer ignorance of Satan and his devices. Even many spiritual believers are unable to wage a successful war against this army of wicked spirits, through lack of knowledge of what is involved. Many shrink from the subject altogether, insisting that so long as Christ is preached, occupation with Satan and demons is unnecessary and spiritually unhealthy. All the while, however, Satan is continuously gaining advantage because of the believer’s ignorance. (Merrill F. Unger, Biblical Demonology, pp. 201-202)
In undertaking to outline the Biblical teaching on Satan, there are three general conditions which will serve as “ground rules.” They are:
The authority of the Scriptures of both the Old and New Testaments will be accepted without question.
Evidence will be drawn from the Word of God alone, since no final light can be found on this subject other than it has pleased God to reveal it in the Bible.
There will be no discussion as to the actual existence of Satan; this being both assumed and taught from Genesis to Revelation.