Why did Gabriel Marcel describe human life as a gift?

Gabriel Marcel, a prominent theistic existentialist, argued that human life is experienced as a gift because of the individual's relationship to an infinite Being.

In his work Homo Viator, Marcel posited that human existence is characterized by a consciousness of owing everything to a transcendent reality, which he often referred to as an "Absolute Thou." Because this infinite Being is the source of all that a person has, and because the creature cannot impose any conditions upon this Being, the experience of life as a gift emerges naturally.

Marcel noted that the concept of a gift inherently implies the existence of a gift-giver. Consequently, he viewed this experience as an indirect argument for the existence of a Supreme Being. This perspective is rooted in his broader philosophical framework, which emphasizes that certain fundamental aspects of human life—such as faith, hope, and love—are "mysteries" that cannot be fully grasped through objective, abstract analysis, but rather through personal involvement and participation in reality.1