This book is organized as a series of letters that calls the church of our age to refocus it's message on the preaching of the Gospel, the sufficancy of Scripture, and the principles of worship as commanded in Scripture.
Each letter(chapter) is written to a certain position in the church(e.g. Minister, Worship Leader, Pianist, ...), yet one can learn so much by reading the entire book.
The book also discusses issues such as what music is glorifying to God, the lack of exalting prayers, returning Selah to worship, and so much more.
This book is a must read for every deacon and overseer, as well as any other Christian who wishes to have a greater understanding of how we are commanded to Worship God.