This paper explores the ontological conception of Gabriel Marcel, with a specific focus on its application to the Daughters of Mary Immaculate (DMI). Gabriel Marcel's philosophical framework emphasizes the importance of existential questions and the human experience of Being. By examining Marcel's ideas and their relevance to the DMI, this study aims to shed light on the process of becoming fully human. The paper analyses Marcel's ontological concepts, including his notions of the concrete and the mysterious, as well as the role of intersubjectivity in human existence. Furthermore, it delves into the particular ways in which the DMI embody Marcel's ideas, highlighting their unique experiences and contributions to the pursuit of human authenticity. Through this exploration, the paper ultimately seeks to provide a comprehensive understanding of Marcel's ontological conception of The Being. The section also addresses the challenges and rewards of their journey towards becoming fully human.