Monotheism

See also what's at Wikipedia, your library, or elsewhere.

• Trinity
• Religion
• Theism
• Pantheism

• God

• The Belief in One God (Philadelphia: S. B. Weston, 1901), by Walter Lorenzo Sheldon (PDF at lvulvu.us)
• Passing on the Faith: Transforming Traditions for the Next Generation of Jews, Christians, and Muslims (New York: Fordham University Press, 2006), ed. by James Heft (PDF with commentary at bepress.com)

Items below (if any) are from related and broader terms.

• The Cosmic God: A Fundamental Philosophy in Popular Lectures (Cincinnati: Office American Israelite and Deborah, 1876), by Isaac Mayer Wise (PDF at americanjewisharchives.org)
• The Doctrine of the New Jerusalem Concerning the Lord (multiple translations), by Emanuel Swedenborg
  • Dick edition: HTML at theheavenlydoctrines.org
  • Potts edition: HTML at theheavenlydoctrines.org
• Does God Exist?, by Herbert W. Armstrong (HTML and PDF with commentary at thetrumpet.com)
• God: An Enquiry into the Nature of Man's Highest Ideal and a Solution of the Problem from the Standpoint of Science (Chicago: Open Court Publishing Co., 1908), by Paul Carus (multiple formats at archive.org)
• God and the Soul: A Poem (New York: The Grafton Press, 1901), by John Lancaster Spalding (multiple formats at archive.org)
• God as Triune, Creator Incarnate, Atoner (A Reply to Muhammadan Objections and an Essay in Philosophic Apology) (1916), by W. H. T. Gairdner (HTML at muhammadanism.org)
• God, the Invisible King, by H. G. Wells (Gutenberg text)
• God the Known and God the Unknown, by Samuel Butler (Gutenberg text)
• God's Way of Peace: A Book for the Anxious, by Horatius Bonar (HTML at CCEL)
• Lectures on the Philosophy of Religion; Together With a Work on the Proofs of the Existence of God, by Georg Wilhelm Friedrich Hegel, ed. by E. B. Speirs, trans. by Jane Charlotte Burdon Sanderson (multiple formats at UIUC and archive.org)
• My God, by Mahatma Gandhi (HTML at archive.org)
• On Union with God, contrib. by Saint Albertus Magnus and P. J. Berthier (multiple formats at archive.org)
• Person and God, ed. by George F. McLean and Hugo Meynell (HTML at crvp.org)
• Principles of Natural Theology (New York et al.: Longmans, Green and Co., ca. 1922), by George Hayward Joyce (HTML at Notre Dame)
• A Romance of Two Worlds, by Marie Corelli
  • volume 1: HTML at Indiana
  • volume 2: HTML at Indiana
  • Gutenberg text
• The Secret of the Universe: "God, Man and Matter" (New York: F. H. Revel and Co., 1932), by Nathan R. Wood (HTML with commentary at sacred-texts.com)
• Social and Philosophical Studies (Chicago: C. H. Kerr and Co., 1906), by Paul Lafargue, trans. by Charles H. Kerr (multiple formats at archive.org)
• Spinoza's Short Treatise on God, Man, and His Well-Being, Translated and Edited, With an Introduction and Commentary and a Life of Spinoza (London: A. and C. Black, 1910), by Benedictus de Spinoza, ed. by A. Wolf (multiple formats at archive.org)

• Absolute Predestination, by Girolamo Zanchi, ed. by Augustus Toplady (HTML with commentary at slu.edu)
• Concerning The Three Principles of The Divine Essence (London: John M. Watkins, 1910), by Jakob Böhme, trans. by John Sparrow, contrib. by Paul Deussen and Charles John Barker (multiple formats at archive.org)
• Discourses Upon the Existence and Attributes of God (with material on his life and character; 2 volumes; New York: R. Carter and Bros., 1853), by Stephen Charnock, contrib. by William Symington
  • Volume I: multiple formats at archive.org
  • Volume II: multiple formats at archive.org
• Lectures on the Pantheistic Idea of an Impersonal-Substance-Deity, As Contrasted with the Christian Faith concerning Almighty God, by Morgan Dix (page images at MOA)

• The Godhood of God, by Arthur Walkington Pink (multiple formats at CCEL)
• Lead Us Not Into Deception: A Biblical Examination of Moral Government Theology (c1981), by Alan W. Gomes (PDF at biola.edu)
• Providence Unfolded (New York: Edward H. Fletcher, 1851), by Alexander Carson (multiple formats at archive.org)

• Waldo, Tell Me About God, by Hans Wilhelm (PDF at childrensbooksforever.com)

• Belief in God: Its Origin, Nature, and Basis (New York: Charles Scribner's Sons, c1890), by Jacob Gould Schurman (multiple formats at archive.org)
• The Knowableness of God: Its Relation to the Theory of Knowledge In St. Thomas (1905), by Matthew Schumacher (HTML at Notre Dame)

• God's Debris: A Thought Experiment, by Scott Adams (PDF with commentary at andrewsmcmeel.com)

• "Deus": Logische Syntax und Semantik (second edition, in German; 2009), by Christoph Zimmer (PDF at zmm.cc)
• What Is His Name?, by Ahmed Deedat (PDF in South Africa)

• Poems About God, by John Crowe Ransom (HTML and TEI at UNC)
• Spirits in Bondage: A Cycle of Lyrics, by C. S. Lewis (Gutenberg text)

• Belief in God (London: J. Murray, 1922), by Charles Gore (multiple formats at archive.org)
• Does God Exist?, by Herbert W. Armstrong (HTML and PDF with commentary at thetrumpet.com)
• The Existence of God: A Dialogue, in Three Chapters (London: Catholic Truth Society, 1887), by Richard F. Clarke (HTML at Notre Dame)
• Foolish Faith: What Today's Information Age Says About God, by Judah Etinger (HTML at foolishfaith.com)
• God: An Enquiry into the Nature of Man's Highest Ideal and a Solution of the Problem from the Standpoint of Science (Chicago: Open Court Publishing Co., 1908), by Paul Carus (multiple formats at archive.org)
• Is Theism a Logical Philosophy?, by Burris Jenkins and E. Haldeman-Julius (HTML at infidels.org)

• No Sense of Obligation: Science and Religion in an Impersonal Universe (c2001), by Matt Young (PDF with commentary at mines.edu)

• Grace, Predestination, and the Salvific Will of God: New Answers to Old Questions, by William G. Most (HTML at catholicculture.org)
• Our Father's Plan: God's Arrangements and Our Response, by William G. Most (HTML at catholicculture.org)

• The Critique of Pure Reason, by Immanuel Kant, trans. by J. M. D. Meiklejohn (Gutenberg text)
• The Logic of Causation (phases 1-3, published 1999-2010), by Avi Sion (frame-dependent HTML at thelogician.net)
• On Causation, With a Chapter on Belief (London: Longman's Green and Co., 1916), by Charles Arthur Mercier (multiple formats at archive.org)

• Desiring God: Meditations of A Christian Hedonist (1996 edition), by John Piper (frame-dependent HTML at desiringgod.org)
• A Hunger for God: Desiring God Through Fasting and Prayer, by John Piper (PDF with commentary at desiringgod.org)
• When I Don't Desire God: How to Fight for Joy, by John Piper (PDF with commentary at desiringgod.org)

• Glory, by Arthur Blessitt (HTML at blessitt.com)

More items available under broader and related terms at left.