The article explores the conceptual distinctions and overlaps between religion and spirituality, highlighting the challenges in defining these constructs for psychological study. It begins by noting the difficulty in operationalizing terms like "spiritual" due to their subjective nature, which has led behavioral scientists to avoid studying spiritual health and disease. Despite this, the psychological study of religion has evolved, with early pioneers like William James and G. Stanley Hall laying the groundwork. The field has experienced periods of neglect, particularly during the rise of behaviorism, but has seen a resurgence in recent years. The article emphasizes the pervasive role of religion in American society, with most Americans maintaining active religious beliefs and practices. However, psychologists tend to be less religious, which may contribute to the underemphasis of religion in psychological research. The text discusses the multifaceted nature of religion and spirituality, noting their roles in psychological development, social behavior, cognitive processes, emotional experiences, and personality. It also highlights their relevance to mental health, drug abuse prevention, and social functions. The article addresses the complexity of defining religion and spirituality, noting that they are multidimensional and often overlap. It presents criteria for defining these constructs, emphasizing the concept of the sacred, a search process, and community support. The text also discusses the distinction between religion and spirituality, noting that spirituality can be more individualized and less institutionalized. It warns against polarizing views of religion and spirituality, emphasizing the importance of recognizing their shared sacred core and the potential dangers of oversimplification. The article concludes by advocating for empirical research and improved operationalization of these concepts to better understand their roles in human experience and psychological well-being. It underscores the need for a balanced and nuanced approach to studying religion and spirituality, acknowledging their complexity and the challenges in defining them.The article explores the conceptual distinctions and overlaps between religion and spirituality, highlighting the challenges in defining these constructs for psychological study. It begins by noting the difficulty in operationalizing terms like "spiritual" due to their subjective nature, which has led behavioral scientists to avoid studying spiritual health and disease. Despite this, the psychological study of religion has evolved, with early pioneers like William James and G. Stanley Hall laying the groundwork. The field has experienced periods of neglect, particularly during the rise of behaviorism, but has seen a resurgence in recent years. The article emphasizes the pervasive role of religion in American society, with most Americans maintaining active religious beliefs and practices. However, psychologists tend to be less religious, which may contribute to the underemphasis of religion in psychological research. The text discusses the multifaceted nature of religion and spirituality, noting their roles in psychological development, social behavior, cognitive processes, emotional experiences, and personality. It also highlights their relevance to mental health, drug abuse prevention, and social functions. The article addresses the complexity of defining religion and spirituality, noting that they are multidimensional and often overlap. It presents criteria for defining these constructs, emphasizing the concept of the sacred, a search process, and community support. The text also discusses the distinction between religion and spirituality, noting that spirituality can be more individualized and less institutionalized. It warns against polarizing views of religion and spirituality, emphasizing the importance of recognizing their shared sacred core and the potential dangers of oversimplification. The article concludes by advocating for empirical research and improved operationalization of these concepts to better understand their roles in human experience and psychological well-being. It underscores the need for a balanced and nuanced approach to studying religion and spirituality, acknowledging their complexity and the challenges in defining them.