“One may protest and ask, ‘Why should God be worshiped in images and not in His original spiritual form?’ The answer is that we cannot see God immediately in His spiritual form. With our material eyes we can only see stone, earth, wood – something tangible. Therefore Krishna comes as archa-vigraha, a form conveniently presented by the Supreme Lord in order for us to see Him. The result is that if we concentrate upon the image and make offerings with love and devotion, Krishna will respond through the image.” (Shrila Prabhupada, Raja-Vidya: The King of Knowledge, Ch 3)