Traditionally oil lamps are used as a symbol of purity, blessings and divinity. It is a common belief in people that when the lamps are lit with oiled wicks, Goddess Lakshmi bestows her blessings. The lamp and its lights emits and generates a positive environment.
It is also scientifically proven that you don't need to be a believer to feel the positive resonance of the light that comes from a oil lamp. Also, Ghee/ Oil used in the lamp, all have different properties, which becomes a part of the energy coming from the lamp.
A lit lamp not just provides light, but also keeps the air around it pure, keeping bacteria/ mosquitoes at bay. Also makes for a excellent decor piece, collective and gifting option.