Why Do We Give Flowers to the Gods?

 From 'Sandalwood and Carrion', chapter The Toilette of the Gods:

In the passage from the Mahabharata, offering the flowers and incense, a non-vedic mode of interaction with the gods, and a mode of interaction shared with other types of divine beings , such as yakshas, is presented in a manner that implies its consistency with two major orthodox vedic paradigms for interac­tions with others: the gift and the sacrifice.. The fragrant flowers are also assigned a place in a cosmogony that links them to other fundamental categories, and then a traditional etymology of a common Sanskrit word for 'flower' is invoked to explain the offering-all these are typical strategies for exploration of tradition in early South Asia.

To people in South Asia who were familiar with later perfume culture, the aromatics described in the Mahabharata would have possibly seemed rather limited and archaic, though guggules appears to have been a particularly enduring feature of religious incenses. At a later period, to someone living in South Asia who was exposed to the elite culture at the Mughal court, where such materials as rose water and ambergris were specially valued, even the more complex temple perfumes and incenses might likewise have seemed rather archaic or traditional, as they often do when used in South Asia or amongst diaspora communities today. The passing of time tends to create an additional division in olfactory aesthetics and material culture in South Asia, in which religion smells of tradition, guggulu based dhup, and sandalwood paste, and this comes to differ even more from the perfumes of 'profane' life.