1. In Praise of Mystery by Ada Limón
  2. In Pursuit of Silence by George Prochnik
  3. In Search of a Prophet by Paul-Gordon Chandler
  4. In Search of the Hidden Treasure by Pir Vilayat Inayat Khan
  5. In Search of Wisdom by Matthieu Ricard, Christophe Andre, Alexandre Jollien
  6. In the Beginning Was the Spirit by Diarmuid O'Murchu
  7. In the Company of the Poor by Jennie Weiss Block, Michael Griffin
  8. In the Eye of the Storm by Gene Robinson
  9. In the Heart of the Temple by Joan Chittister
  10. In the House of Remembering by Kabir Helminski
  11. India by Diana Eck
  12. Infinite Circle by Bernie Glassman
  13. Infinite Life by Robert Thurman
  14. Inner Revolution by Robert Thurman
  15. Inner River by Kyriacos C. Markides
  16. Insane for the Light by Ronald Rolheiser
  17. Inside Out Box of Mixed Emotions by Brittany Candau
  18. Inside the Miracle by Mark Nepo
  19. Instant Enlightenment by David Deida
  20. Integral Life Practice by Adam Leonard, Ken Wilber, Marco Morelli, Terry Patten
  21. Integral Spirituality by Ken Wilber
  22. Interactive Faith by Bud Heckman, Rori Picker Neiss
  23. Interfaith Leadership by Eboo Patel
  24. Into the Heart of Life by Jetsunma Tenzin Palmo
  25. Into the Tangle of Friendship by Beth Kephart
  26. Invisible Heroes by Belleruth Naparstek
  27. Is Was by Deborah Freedman
  28. Islam Is . . . An Experience of Dialogue and Devotion by Mary Margaret Funk
  29. Island Storm by Brian Floca
  30. It's a ... It's a ... It's a Mitzvah by Diane Heiman, Liz Suneby
  31. It's Hard to Make a Difference When You Can't Find Your Keys by Marilyn Paul
  32. It's Not The End of the World by Joan Borysenko
  33. It's Our Nature by Rebeca Orozco
  34. It's Really All About God by Samir Selmanovic
  35. Jake Fades by David Guy
  36. Jesus by Laurence Freeman
  37. Jesus Today by Albert Nolan
  38. Jesus, Companion in My Suffering by Joyce Rupp
  39. Jewish Dharma by Brenda Shoshanna
  40. Jewish with Feeling by Joel Segel, Zalman Schachter-Shalomi
  41. Joan Chittister by Joan Chittister, Mary Hembrow Snyder, Mary Lou Kownacki
  42. John Muir by Thomas Locker
  43. Journey by Aaron Becker
  44. Journey to the Heart by Kim Nataraja
  45. Joy by Corrinne Averiss
  46. Joy on Demand by Chade-Meng Tan
  47. Judaism Is About Love by Shai Held
  48. Judaism without Tribalism by Rami Shapiro
  49. Just Because by Melannie Svoboda
  50. Just Breathe by Mallika Chopra
  51. Just For Today by Saint John XXIII
  52. Kabbalah by Lawrence Kushner
  53. Kabbalah and the Power of Dreaming by Catherine Shainberg
  54. Kahlil Gibran's Little Book of Life by Neil Douglas-Klotz, Kahlil Gibran
  55. Kahlil Gibran's Little Book of Love by Neil Douglas-Klotz
  56. Karmic Relief by Philip Goldberg
  57. Keep Going by Joseph M. Marshall III
  58. Keep Your Courage by Carter Heyward
  59. Keeping Silence by C. W. McPherson
  60. Keeping the City Going by Brian Floca
  61. Keeping the Faith Without a Religion by Roger Housden
  62. Kindred Spirits by Allen M. Schoen
  63. Kindred Spirits by Leslie Stall Widener
  64. King Calm by Susan D. Sweet, Brenda S. Miles
  65. Kneeling with Giants by Gary Neal Hansen
  66. Knitting into the Mystery by Susan S. Izard, Susan S. Jorgensen
  67. Kuan Yin by Maya van der Meer
  68. Last Child in the Woods by Richard Louv
  69. Late Today by Jungyoon Huh, Aerin Park (translator)
  70. Laugh Your Way to Grace by Susan Sparks
  71. Laughter Yoga by Madan Kataria
  72. Leadership in Turbulent Times by Doris Kearns Goodwin
  73. Leap by Terry Tempest Williams
  74. Leap Before You Look by Arjuna Ardagh
  75. Learning from the Heart by Daniel Gottlieb
  76. Learning the Language of the Fields by Daniel G. Deffenbaugh
  77. Learning to Fall by Philip Simmons
  78. Learning to Pray by James Martin
  79. Learning to Walk in the Dark by Barbara Brown Taylor
  80. Ledger by Jane Hirshfield