G. H. Gerberding, The Way of Salvation in the Lutheran Church (Philadelphia: Lutheran Publication Society, 1887).
This book is a tonic against the errors of revivalism, decision theology, Enthusiasm, etc. It explains plainly and in positive terms how sinners are saved in the Lutheran church. Among many other things, it speaks significantly to the use of the Small Catechism. It was written for the common people; also for use in Luther leagues, adult Bible and catechetical classes.
See Amazon reviews here.
Amazon offers a Kindle edition with a price of $0.00.
Google offers it as a free ebook in EPUB and PDF formats here.
The Internet Archive offers digitized editions by several different organizations. The edition by Princeton Theological Seminary Library is available in ABBYY GZ, B/W PDF, Daiy, EPUB, Full Text, Kindle, PDF, and other formats here.
The Gutenberg Project offers a free digital edition here.
The Hathi Trust offers a digitized version here.
Forgotten Books members can download it, and Forgotten Books lets anyone including nonmembers read it online for free here.