The work on the book was well along when Ellen White and her staff returned to the United States in the late summer of 1887. The completion of the work was the first task to which she gave attention as she and her helpers settled in her Healdsburg home. Her last writing for the book was for the author's introduction, carrying the date of May, 1888. Here she made a comprehensive statement in the setting of the work of God's prophets, regarding God's commission to her to write the book. She declared: 3BIO 441.1
Through the illumination of the Holy Spirit, the scenes of the long-continued conflict between good and evil have been opened to the writer of these pages. From time to time I have been permitted to behold the working, in different ages, of the great controversy between Christ, the Prince of life, the Author of our salvation, and Satan, the prince of evil, the author of sin, the first transgressor of God's holy law.—The Great Controversy, x. 3BIO 441.2
Being instructed “to trace the history of the controversy in past ages, and especially so to present it as to shed light on the fast-approaching struggle of the future” (Ibid., p. xi), she informed the reader that in pursuance of this purpose she had endeavored to select and group together events in the history of the church. She pointed out that these records presented a foreshadowing of the conflict that lay ahead. Taking this in the light of God's Word and the illumination of the Holy Spirit, she unveiled devices of the great adversary, Satan. Then she took up the matter of her reference to and use of historical writings. 3BIO 441.3
She explained how she employed quoted material as a matter of convenience, an aid to her writing: 3BIO 441.4
In some cases where a historian has so grouped together events as to afford, in brief, a comprehensive view of the subject, or has summarized details in a convenient manner, his words have been quoted; but in some instances no specific credit has been given, since the quotations are not given for the purpose of citing that writer as authority, but because his statement affords a ready and forcible presentation of the subject.—Ibid., xii. 3BIO 441.5
She had drawn from denominational authors also in presenting views on prophecy. She had been with the pioneers of the church as they earnestly studied Bible doctrines and prophecy. Conclusions were arrived at jointly, and at times one would be the writer to set them before the public, and at times another. She informed her readers: 3BIO 441.6
In narrating the experience and views of those carrying forward the work of reform in our own time, similar use has been made of their published works.—Ibid. 3BIO 442.1
This would apply particularly to J. N. Andrews and Uriah Smith, and at times to her husband, James White. 3BIO 442.2