The world has been willing to comply with the wishes and projects of Satan to the extent of ceasing to believe that he really exists; this unbelief being most advantageous to his present undertakings. Yet the opinions of men have never changed the facts of revelation, and, according to Scripture, Satan exists; still possessed with great power and influence over the affairs of men-a power and influence to be increasingly dreaded as this present age advances. If any word of mine shall add to the number of the readers of this book I shall be glad to have written it; and I sincerely wish that all believers, and especially all ministers and Christian workers, might in some way be led to read it. The 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.