There are various origins attributed to this festival. In Bengal, the festival is dedicated to the worship of Goddess Kali. In some parts it is also celebrated to commemorate the day on which Lord Rama returned to Ayodhya with His wife Sita and brother Laxmana after defeating Demon King Ravana. Some part of India celebrates it as the marriage of Goddess Lakshmi with Lord Vishnu. These are the historical significance of the festival.
Little clay lamps are lit as an offering to God to ward off evil spirits and to usher prosperity. This is also to welcome the new year on the following day, when businessmen start their new account books. It is an auspicious day for new beginnings. This is a festival of brotherhood, peace and harmony too because people from all religions are celebrating Deepavali in India.
May the divine light of Diwali shine with Peace, prosperity, happiness & good health in your life. HAPPY DIWALI.