In Denmark, religious behavior is usually very private. Little is known of religious and spiritual needs of patients and family during critical illness and hospitalization. We aimed to explore contemporary thoughts and prayers related to critical illness and hospitalization expressed in hospital chapel Guest Books. Qualitative content analysis of written texts was performed on Guest Books completed from 2005–2019. We identified the main themes of health and illness, life and death, and science and religion. Visitors welcomed the Guest Books as a place to express religious and spiritual thought, even in a nominally nonreligious society.