Although Weil always took Judaism, Jewish history, and the Jewish community seriously, in her later years she began to probe more and more deeply into Biblical texts. She mused about the meaning of episodes from Jewish history, believing that only by studying history could Jews learn important lessons about the evolution of their religion and its ideals. In her 80th year, for example, she wrote that the story of Abraham became more than ever for her a story of obedience to conscience, while that of Jacob was about the discovery of the great religious truth about "the universality of God, the idea that God is God of the whole world."

Judaism, for Weil, was a religion of daily life, of kindness and goodness, yet also one that offered profound satisfaction in a spiritual oneness with God. In a signed note written in 1955, entitled "My Concept of God is Creative Essence, Ultimate Reality, Infinite Truth, Universal Being," she underscored this belief:

Being finite ourselves, we human beings cannot know God directly, but only through the phenomena, or manifestations of God in our universe. These manifestations range from the distant world of the milky way to the tiniest blade of grass, from the vast oceans to the dew drop, from the grandest mountain to the soft skin of a baby's cheek; they include every act of kindness and generosity and sacrificial devotion of a human being to another human being, the love of a man for his wife, the love of a mother for her child. They include our very search for God—They include all the beauty and the glory and the mystery of the universe around us and within us. The more we grow in wisdom and in the understanding of these things, the more nearly we can approach to a knowledge of God.

For Weil, religion was a "whole-person" affair involving "reason, emotion, science, mystery—whatever constitutes a person's approach to understanding the universe & his own relation to it." She considered Christianity's "terrific emphasis on Sin" problematic, preferring the Jewish teaching that "men should look into their own lives, see their many doings, their sins (if you will), repent of them, [and] lead bettter lives than [in] their past."