Objectives: The purpose of this review is to provide an overview of research on spirituality and religiosity in the intensive care setting that has been published since the 2004–2005 American College of Critical Care Medicine (ACCM) Clinical Practice Guidelines for the Support of Family in the Patient-Centered Intensive Care Unit with an emphasis on its application beyond palliative and end-of-life care. Materials and methods: ACCM 2004–2005 guidelines emphasized the importance of spiritual and religious support in the form of four specific recommendations: [1] assessment and incorporation of spiritual needs in ICU care plan; [2] spiritual care training for doctors and nurses; [3] physician review of interdisciplinary spiritual need assessments; and [4] honoring the requests of patients to pray with them. We reviewed 26 studies published from 2006 to 2016 and identified whether studies strengthened the grade of these recommendations. We further categorized findings of these studies to understand the roles of spirituality and religiosity in surrogate perceptions and decision-making and patient and family experience. Conclusions: Spiritual care has an essential role in the treatment of critically ill patients and families. Current literature offers few insights to support clinicians in navigating this often-challenging aspect of patient care and more research is needed.