This year Diwali, a popular festival for Hindus, Jains, Buddhists and Sikhs, will be celebrated on 24 October, the Amavasya, or new moon day, of the month of Kartik in the traditional Indian lunar calendar. Devotees across around the world will bring festivities into their homes by lighting earthen lamps called diyas, setting off fireworks, displaying coloured electric lights and exchanging gifts. In northern India, this date also marks the beginning of the new year. The day is specially dedicated to the worship of Lakshmi, the Hindu goddess of prosperity and good fortune. Who is Lakshmi? In modern images, Lakshmi is typically depicted wearing either a red or a green sari. The upper two of her four hands are holding lotus flowers, while her lower right hand is upraised in the “do not be afraid” gesture, or abhaya mudra. Her lower left hand is pointed downward with her palm facing out and golden coins are falling from it. She sits or stands upon a large red lotus flower. Often, the...