diogenesister: I wonder if this book is available on project Gutenburg??
There are several copies listed at archive.org. This book is available in several formats.
https://archive.org/search.php?query=the%20gates%20ajar
Utopian literature of the late 19th century would have influenced Russell's writings, for sure. After all, Russell didn't set out to create a religion, he wanted to sell his books. The religion happened after his books were written, not before.
Here is another utopian book that was popular around the same time - it was written just prior to "Gates Ajar" and could have been on Russell's bookshelf as well.
"Gates Wide Open" by George Woods.
https://archive.org/details/gateswideopenors00wood
An edition of this work, entitled " Future Life ; or, Scenes in Another World," was published by Derby and Jackson in the fall of 1858. The firm failed in the spring of 1859, and the plates were resold to the author, and have remained in his possession unused until the present time, when the recent popular and attractive book of Miss Phelps, entitled " The Gates Ajar," suggested its republication and the change of title which is now made. The Author hopes his readers will be gratified witli this attempt to picture the Scenes and Society of Another World. Washington, May 1, 1869.
Russell was not a great prophet - he was a just a product of his culture who took advantage of the free capitalist market in America in the late 19th century. Utopian (and dystopian) literature was quite popular at the time.
*to add - Phelps published two sequels to Gates Ajar:
"Beyond the Gates"
https://archive.org/search.php?query=beyond%20the%20gates
"The Gates Between"