Answered By Pt Sri Pranesh Achar (Ananda Rangan)
Pooja
First of all, before beginning the worship of God, one lamp must already be kept burning continuously in the prayer room. This means there should always be a lamp glowing in the house of God. This is called the Akhand Deepa (ever-burning lamp).
Apart from this, in front of the deity, a special lamp should be lit either before or after performing the incense (Dhoopārati).
There is no fixed number for how many such lamps should be lit.
However, there is an important rule:
We should not place only one lamp before God. Lamps must be placed in pairs.
Even if a lamp has multiple wicks, one should not light only a single wick; at least two wicks should be lit together.
Such an arrangement is called a Sālu Dīpa (row or paired lamps). We may place as many such pairs as we wish.
At the very least, one pair of lamps must be offered.
Lighting a lamp is said to bestow great merit. The Skanda Purāṇa states:
“All the sins committed from birth, whether by a man or a woman, are destroyed by offering a lamp to Lord Vishnu.”
This means that all sins accumulated since birth are destroyed when a lamp is lit and offered to God.
Just as lighting a lamp before God is very sacred, offering that lamp in charity—especially to Brahmins or guests on special occasions after it has been offered to God—brings even greater merit.
This is taught by the Purāṇas and Smṛtis (scriptures).
