Sources include Herbert, Hopkins, Donne, Christina Rossetti, Cowper, St Anselm, Cardinal Newman, Bunyan, Blake, Bonhoeffer, Emily Dickinson, Herrick, Wesley, Mother Theresa, Tennyson, Spenser, Simone Weil, Kierkegaard, St Francis, the Book of Common Prayer, the Bhagavad Gita, Buddhist Scriptures, the Dead Sea Scrolls.