Once we were walking around Sri Radhakunda paying respects to each of the presiding Deities there. A young western boy was with us among the group, and it was noticed that he avoided seeing and offering his respect to each and every sacred image of the Lord they visited on the way. When devotees gently questioned him about his strange behaviour, he replied that as a Christian he was exclusively worshipping God, but not stones and idols. Hearing this one devotee asked him if he believed in the omnipresence of God, and the boy answered that he did. To this the devotee replied that because of God's omnipresence he should give respect to Him also in front of the 'stones' and 'idols', especially if they are God's representations and in such a Holy place.
In the Padma Purana it is mentioned:
arce vishnau shiladhir gurushu naramatir vaishnave jatibuddhir vishnor va vaishnavanam kali mala mathane pada tirthe'mbu buddhir shri vishnor namni mantre sakala kalusha shabde samanya buddhir vishnau sarveshvareshvare tad itara samadhir yasya vai naraki sah
"A person who considers the Deity of Vishnu to be a mere stone, his superiors to be mere human beings, Vaishnavas to belong to a certain caste, the water that has washed the feet of Vishnu and the Vaishnavas to be mere water, although they are holy waters that destroy all the filth of the age of Kali, the holy name or the diksha-mantra of Sri Vishnu, that destroys all sins, as ordinary sound vibrations, and who considers Vishnu, who is the Lord of all Lords, similar to all other gods (devas - demigods), is a resident of hell."
To Moses the Lord appeared in the form of a burning bush, to Mohammad He appeared in the form of sound, for Sri Prahlad He appeared coming out of a stone pillar. If He is everywhere, even within our stone like hearts, then why not in the form of the Shila?