When World War I broke out in 1914, he was called on for addresses on The War and Prophecy. Then God laid it on his heart to prepare a work on Dispensational Truth (or God's Plan and Purpose in the Ages), containing a number of charts with descriptive matter. He spent three years of his life designing and drawing the charts and preparing the text. The favorable reception it has had since it was first published in 1918 seems to indicate that the world was waiting for such a book.
Because it had a large and wide circulation in this and other lands, the first edition was soon exhausted. It was followed by a second edition, and then, realizing that the book was of permanent value, Larkin revised it and expanded it, printing it in its present form. Larkin followed this masterpiece with other books: Rightly Dividing the Word, The Book of Daniel, Spirit World, Second Coming of Christ, and A Medicine Chest for Christian Practitioners, a handbook on evangelism.
Larkin, a kind and gentle man, deplored the tendency of writers to say uncharitable things about each other, so he earnestly sought to avoid criticisms and to satisfy himself with simply presenting his understanding of the Scriptures. Though he did not intend to publish his own works, the Lord led in that direction. During the last five years of his life, the demand for Larkin's books made it necessary for him to give up the pastorate and devote his full time to writing. He went to be with the Lord on January 24, 1924.