In its spiritual sense, Holi is a celebration of triumph of good over evil or human's conquest of carnal desires. Holika Dahan on the eve Holi is meant to remind us the power of pure devotion to the supreme soul and significance of Kama Dahan or burning of desires in human life to achieve Nirvana.
Essentially, in Hindu philosophy and mythology, Holi means conquest of sensual values by spiritual values. As Lord Krishna says in the Bhagavad Gita says that by contemplating on sensual objects, persons become attached to them and get trapped by lust which in turn generates anger. Consequently, anger leads to delusion and loss of discretion resulting in the downfall of the person or becoming an evil person.
At the time of Holi festival, the tender green leaves appear on the trees, flowers bloom, and the chirping of birds mark the advent of Spring season considered to be best period for contemplation, meditation and spiritual practices. There is a splurge of colors, soothing sounds and an aura of fragrance of flowers all around at advent of Holi.
Thus, Holi announces the arrival of spring and the passing of winter. It reminds the people to bury their hatchets with a warm embrace and throw their sensual desires and vices to the wind. Holi also solemnizes the divine and pure love of Radha and Krishna. According to saibabaofindia.com, no other festival brings home the lesson of spiritual and social harmony as well as the festival of Holi.