Lord Shiva is represented by Lingam. The form of Lord Shiva is the Lingam. This is representing the supreme lord who has no shape. The shape of the Lingam represents the live power of nature. The devotees will worship the Lingam as a mark of respect to the creator of universe.
The devotees will describe Shiva Lingam as a supreme power and it does not have shape. The devotees believe that the Lingam has very good powers which will remain silent until the time arrives. The omnipresent Lord Shiva will be available in all the places. God is not having any shape. This is mainly represented by the shape of Shiva Lingam. The silence of the Lingam will converse with the devotees who believe in him.
Lord Shiva has indescribable powers. Lord Rama and King Ravana worshipped Lingam or getting more powers. This is the reason why devotes worship Lingam. The temples of Shiva will have many mystical powers. The lingam is the cleanliness of the soul. The people who worship Lord Shiva will get peace of mind and will get a lot of prosperity in life. The shape of the lingam is that of flame.
The fire is sacred and represents the birth of the humans. The Lingam is merely the symbol of Lord Shiva. The simple shape of Lord Shiva will represent the simple form of worship. The main god is formless and is represented by the Lingam. The worship is very simple and the devotees will feel everything is simple.