"Vigraha means the form of the Lord. There are eight kinds of the forms of the Lord. They are made of stone, they are made of wood, they are made of jewels, and sometimes they are made of painting, and metal. So many. There are eight. All these vigrahas are to be worshiped. That is mentioned in the sastras. Painting also. If there is painting or even if you think of the form of the Lord within the mind, that is also vigraha. Just like dhyanavasthita-tad-gatena manasa pasyanti yam yoginah [SB 12.13.1]. The yogis, they think of Visnu form within the core of the heart. That is also vigraha. Don't think that is imagination. That is also vigraha. So there are eight kinds of vigrahas, and each and every one of them are as good as the other. Similarly, vigraha of guru is also... Saksad-dharitvena samasta-sastraih. This is the injunction of the sastra. And... 'May be in the sastra, but it is not carried.' No, it is carried... it is said, tatha bhavyata eva sadbhih. Those who are aware of the sastras...
"Just like we have installed the Deity according to sastra. There is nothing imaginary. It is not idol worship. Idol worship is different. Just like in the Western countries they put an idol on the street, on the park, as the resting place of the crows and passing stool on the head. That is idol worship. The so-called statues are installed and without any protection... No. Our worship is not idol worship. This is Deity worship. We construct temple and spend lakhs of rupees to install the Deity. It is not idol worship. Idol worship is different. Therefore it is warned, arcye visnau sila-dhih. If somebody thinks that the vigraha is idol worship... There are so many rascals, they think like that. They are... 'Why you are worshiping in the temple?' Amongst the Indians also, the Arya-samajis, they protest against temple worship. But who cares for them? Here in Vrndavana, there is Arya-samaji temple. Nobody goes there. But this is a new temple recently started, and thousands of people are coming. Why? All of them are fools and rascals? This is exactly according to the sastra."
(Note: The Sanskrit word sastra means the revealed scriptures in the English language,)
(Srila Prabhupada lecture, Vrindavana, India, October 5, 1976)