Everett L. Worthington Jr. (Ph.D., University of Missouri) is professor of psychology at Virginia Commonwealth University. He is a licensed clinical psychologist and former executive director of the Templeton Foundation's A Campaign for Forgiveness Research. Worthington has studied forgiveness since the 1980s and has published more than two hundred articles and papers on forgiveness, marriage and family, psychotherapy and virtue in a wide variety of journals and magazines. He was the founding editor of Marriage and Family: A Christian Journal and sits on the editorial boards of several professional journals. He has appeared on Good Morning America, CNN and The 700 Club and been featured in award-winning documentary movies on forgiveness such as The Power of Forgiveness and The Big Question. He is the author of seventeen books including Handbook of Forgiveness, Hope-Focused Marriage Counseling and Forgiving and Reconciling.

McCullough (Ph.D., Virginia Commonwealth University) is associate professor of psychology at the University of Miami in Coral Gables, Florida. Formerly, he was director of research for the National Institute for HealthCare Research (NIHR) in Rockville, Maryland.

Steven J. Sandage (PhD, LP) is the Albert and Jessie Danielsen Professor of Psychology of Religion and Theology at Boston University and research director and senior staff psychologist at the Danielsen Institute. He has faculty appointments at Boston University in the School of Theology, the department of Psychological and Brain Sciences, and the graduate division of religious studies. His co-authored/coedited books include To Forgive is Human, The Faces of Forgiveness, Transforming Spirituality, The Skillful Soul of the Psychotherapist, and Forgiveness and Spirituality: A Relational Approach. He has also published articles and chapters on forgiveness, humility, spirituality in psychotherapy, psychology of religion, intercultural competence and social justice, narcissism, borderline personality disorder, and suicide, among other areas. Sandage's research has been funded by the John Templeton Foundation, the Lilly Endowment, and the Fetzer Institute. Currently, he practices as a Licensed Psychologist at the Danielsen Institute with clinical specializations including couple and family therapy, multicultural therapy, and spiritually-integrative therapy. He also provides diversity training for mental health, educational, ministry, and business settings.