Although Leaves of Grass incorporates elements of various world religions in its spiritual vision, Christianity is by far the most important religion represented. Whitman drew ideas from Transcendentalism and the Protestant faiths of antebellum America—for example, the Quakers, Puritans, and Congregationalists—that prized personal experience, personal revelation, and personal relationship to the divine. Equality, simplicity, friendship, and inner light as spiritual intuited truth and intimate relation with the divine—all at the center of Whitman’s thought—are central Quaker values. The radical Quaker, Elias Hicks, a neighbor and friend of the Whitmans, preached that God could be seen in a leaf of grass. As with Puritanism and Transcendentalism, the particulars of nature can be read for signs of eternal purpose and order. Life continues; death is a return to the loving being that gave life.
Whitman took other biblical ideas into his idea of spiritual democracy: The poet is a younger comrade/lover/heir of a Pauline elder-brother Christ, as are all men and women. He moves among others looking through the eyes of the divine and bringing a healing vision of equality, acceptance, and love. The kingdom of God is present within and is celebrated in a “now” that Whitman externalizes as the spiritual democracy. Love, equality, creative energy, and union characterize the divine and characterize America. The United States is chosen to advance the world spiritually.
Some critics describe Whitman as post-Christian because he devised an imaginative vision of the spiritual; equated body and soul; did not believe in Christ as Savior in a traditional way; and encouraged each person to “filter” one’s truth from oneself. The “I” stands prominently at the center instead of God, and although this “I” is closest to the large self of the Hindu Vedantics, it shifts without clear borders among self, personal “I,” representative American, and everyman. Natural symbols and human experience are the inspiration for faith; but this route made possible a common expression of spiritual experience in a nation with so many varieties of Christian beliefs contentiously at odds with each other.