The search for mystery, as a manifestation of what is sacred in life, directs the desire of the men and women of our time, inciting them more and more. Simone Weil offers us a model, both in her biography and in her writings, in search of mystery at the heart of human experience. What is the extent and the meaning of her personal testimony that we can find within the limits between what is necessary and what is gratuitous: on one hand mystic, because the desire of the human heart goes beyond objects of gratuity which are produced in our technical-scientific society, and on the other hand ethic, establishing a source of meaning that guides actions, sustained by good? From the reading and interpretation of the works from the social and particularly the religious period of Simone Weil, we attempt to answer this classic question of theology, showing the convergence between the mystery of absolute gratuity, present in the limits of human experience, bearing in mind the notions of Attention, De-creation, Mediation and Taking Root, and the struggle on behalf of those who are humiliated, through the compassion and the solidarity of God in those human beings inhabited by grace.