(from the description at Monergism.org)
The One True God is a unique kind of workbook, intending not just to teach truth but to lead to an encounter with the living God. Beneath that goal the book aims to ground believers in orthodox Christian theology and the actual contents of the Bible. Students are encouraged to thoughtfully draw conclusions from the Scriptures rather than to merely absorb the principles, inferences, and illustrations set before them by the author. For this reason the book does not include such material and instead focuses on digesting the Scriptures directly.
Through God's own words and under various systematic headings the book unfolds the nature of God. In this way the reader is set on a firm foundation and will readily perceive the centrality and high authority of biblical doctrine within the Christian life. It is the author's conviction that the study of doctrine is both an intellectual and devotional discipline. Therefore students are guided throughout the study to think through and apply the truths they learn, meditating on the demands of Scripture for their heart and mind. The book puts us squarely in the middle of the material, and demands we give searching thought to how we will live before such a God.
This workbook is especially suited for the following contexts: (1) doctrinal training for new converts; (2) college or adult Bible studies; (3) private study; (4) Christian or home school curriculum; (5) Sunday school material; (6) an aid to parents in teaching the Word of God to their children.
"In The One True God , Paul Washer has provided a sound, biblical, substantive theological study for those of us who have been longing for more. Anyone interested in bolstering their understanding of the Doctrine of God will find this study immensely valuable. Moreover, since The One True God is expositional in nature, it can also serve as a teaching tool to give young believers a solid foundation, or to aid in evangelizing unbelievers."
--Voddie Bauchum, Author of Family Driven Faith
"Paul David Washer's study guide on the doctrine of God, The One True God , is the best introductory work known to me. It sets out great truths in clear and balanced form. Human authorities are not quoted but it is evident that the author is familiar with the literature of historic Christianity and accordingly he misses the pitfalls into which others might fall. Young Christians could scarcely spend their time better than working carefully through these pages."
--Iain H Murray, Banner of Truth
"The One True God will lead you through a profitable exercise in biblical and systematic theology. You will learn what the Bible says about the character and attributes of the God who is truly like no other. This is a wonderful work that I pray will help many grow in knowing God. Read it and be blessed. Read it and worship your God."
--Daniel L Akin, President of Southeastern Baptist Theological Seminary