During Navaratri, Goddess Durga is invoked first to remove impurities from the mind.
The Goddess Lakshmi is invoked to cultivate the noble values and qualities. Finally,
Saraswati is invoked for gaining the highest knowledge of the Self. This is the
significance of the three sets of three nights when all these three are gained subjectively,
and then there will be Vijayadashami, the day of true victory.