Even if that were the case, such temporary worship cannot be called eternal dharma. The worship of the eternal vigraha as performed in vaisnava-dharma is eternal dharma.
The vigraha worshiped by the Vaisnavas is not like that. Bhagavan is not formless like brahma. On the contrary, He is the all-powerful, concentrated embodiment of eternity, knowledge, and bliss. The Deity that the Vaisnavas worship, is also all-powerful, concentrated embodiment of eternity, knowledge and bliss. It is that sac-cid-ananda-ghana-vigraha, that is the worshipable Deity of the Vaisnavas. Bhagavan’s transcendental form of eternity, bliss, and knowledge, is first revealed in the pure consciousness of the jiva, and then it is reflected in the mind.
The external form of the Deity is fashioned according to this transcendental form revealed in the mind, and by the power of bhakti-yoga, the sac-cid-ananda form of Bhagavan then manifests in the Deity. When the devotee sees and beholds the Deity, that Deity unites with the transcendental form of Bhagavan that the devotee sees in his heart.
The Deity that the jnanis worship, however, is not like that. They think that the Deity is a statue made of material elements, but that the state of brahma is present in it while they are conducting their worship, and that it becomes a mere material statue again, after they have finished their worship.
Now you should consider the difference between these two conceptions of the Deity and their respective methods of worship. When you obtain Vaisnava initiation by the mercy of a genuine guru, you will be able to correctly understand this difference by observing the results of both.
Vaisnavas are not just fanatics driven by blind faith; rather, they are endowed with subtle and discriminating insight. There is a major difference between the worship of the sri-murti and the temporary worship of an imaginary form of the Lord that has been imposed on a material object. There is no difference in the external procedures of worship, but there is a vast difference in the faith of the two worshipers. The jnanis’ worship is merely an attempt to cheat Sri Bhagavan. This topic will be discussed at a later time.