Fr. Herrera studied for the Archdiocese of Los Angeles for six years and then entered the Society of Jesus. After ordination, he worked as a parish priest in Hollywood, California. After studies in Near Eastern Languages and Literatures at Yale, he moved into neuropsychology and worked at the Neuropsychiatric Institute at UCLA with the Brain Injury Research Center.
He served at St. John’s Seminary College for 8 years and was the Director of Spiritual Formation, Senate president and chair of the Social Sciences Department. He was Director of Spiritual Formation and Psychological Services at the Pontifical College Josephinum and was spiritual father at the Collegio Bellarmino in Rome for three years. He was director of the Centro Joseph Ratzinger in Rome while working with the Ratzinger Stiftung.
He has taught Psychology and Theology as well as Greek and Latin for the Pontifical Anselmo, the Pontifical Santa Croce, and the Gregorian University in Rome. He served seven years as a Spiritual Director at the Pontifical North American College in Rome. He has extensive experience with retreats for seminarians.