Gregory, Jacob. Invisible Fight: Fight the Good Fight of the Faith. Bronx, NY: The Written Ministry of the Word of God, ca. 1955. 
Printed green wrappers, wrappers faded, 5 1/2 x 8 inches, 92 pp., light bump bottom corner. Good. Paperback.
WorldCat has an entry, but no recorded holdings for this item.
The statement of faith at the beginning of the book would place the author in the premillennial fundamentalist Baptist camp, yet he is not listed in Starr's Bibliography nor in Dollars' History of Fundamentalism.
A thorough treatment on waging the war against sin in your personal life.