Kristy Nabhan-Warren is a professor of religion at the University of Iowa. She has written widely on the role of the Virgin Mary in Latino cultures. Her research focuses on Catholic studies. She is the author of Meatpacking America: How Migration, Work, and Faith Unite and Divide the Heartland.

Elizabeth A. Johnson is a religious sister of the Congregation of St. Joseph and a theologian at Fordham University in the Bronx, N.Y. She is one of the foremost feminist theologians and has written extensively on the Virgin Mary, including the book Truly Our Sister: A Theology of Mary in the Communion of Saints.

Lesley Hazleton is a former psychologist and journalist and is the author of Mary: A Flesh-and-Blood Biography of the Virgin Mother. Hazleton lives in Seattle and describes herself as having “deep roots in both Judaism and Catholicism.”

Kelly McGonigal is a health psychologist and lecturer at Stanford University in California. She is also a yoga teacher and has written about yoga and gratitude.

Philip Watkins teaches psychology at Eastern Washington University in Cheney. He specializes in gratitude and has researched its relationship to spirituality.

Jan St. John is producer and host of Radio Gratitude, a San Francisco based-program that spotlights gratitude and altruism.

Sonja Lyubomirsky is a professor of psychology at University of California, Riverside. She studies human happiness. She has researched the effects of “counting one’s blessings” as a way of enhancing happiness.

Joan Borysenko of Colorado is an author and Harvard-trained medical scientist who specializes in mind-body topics. She has written about gratitude.

Jay Marshall wrote Thanking and Blessing: The Sacred Art. He is dean of the Earlham School of Religion in Richmond, Ind., and a Quaker minister.