The soul's safety is in its heat. Truth without enthusiasm, morality without emotion, ritual without soul, make for a Church without power. Destitute of the Fire of God, nothing else counts; possessing Fire, nothing else matters.

The one concern of the devil is to keep Christians from praying. He fears nothing from prayerless studies, prayerless work, and prayerless religion. He laughs at our toil, mocks at our wisdom, but trembles when we pray.

• The Call to Christian Perfection (1943) 44 page e-book in PDF format, accessed October 22, 2006.
• Online version in HTML format accessed October 22, 2006.
• Humanity and God, (1905), 356 pages, ASIN B00089ZBA2.
• The Path of Prayer, (2001), 132 pages, ISBN 0-87508-578-4. Online version in HTML format accessed October 22, 2006.
• The Way to Pentecost (1932) 64 page e-book in PDF format, accessed May 31, 2008.
• Online version in HTML format accessed October 22, 2006. Also see 170 page reprint (2001), ISBN 0-87508-579-2.

• "Spirituality: Do Our Sermons Promote It?" by Edward Braislin, reviewing, inter alia, Humanity and God (1905) by Samuel Chadwick in the American Journal of Theology, Vol. 10, No. 3 (Jul., 1906), pp. 570-576.
• Samuel Chadwick, Oxford Dictionary of National Biography.