Sant Namdev (or Bhagat Namdev in Sikh literature), was 13th century Marathi saint, who was contemporary of Sant Dnyaneshwar, Gora Kumbhar and other very well known Marathi saints.
Namdev was a huge devotee of Pandurang in Pandharpur. For him, “Padurang was everything” and he use to spend a lot of time everyday visiting temple and singing bhajans while seating there.
One day, all these contemporary saints decided to meet in Gora Kumbhar’s house to share experiences. During the discussion, they decided to evaluate each other’s progress, and Gora Kumbhar was made the judge.
Gora assessed that everyone was ripe, except Namdav, who needed more abhayas. That made Namdav furious, as in his opinion, he was the biggest devotee of Pandurang, and there was no way he was not ripe. Finally, he was asked to meet Vishoba Khechar (another saint during that time) to resolve the matter.
Namdev went looking for Vishoba, and found him sleeping in a shiva temple, with this legs facing Shiva-Linga. Namdev did not like that, as in his opinion that was insulting the god, so Namdev woke him up and told him, not to put legs towards god. Visoba, being Visoba, asked him to move his legs where there is no shiva.
Namdev tries to move Visoba’s legs in every possible directions, to his surprise he found shiva linga everywhere.
This experience helped Namdev understand that Pandurang is not only in temple, but it’s everywhere, including in the idol.
The idols in the temple are made to help us get started on the spiritual path, and as we makes progress, we needs grow up form “God Only in the temple” to “God everywhere, including in the Temple”.
This is covered very aptly by Namdev himself, in Guru Granth Sahib.
एकै पाथर कीजै भाउ ॥दूजै पाथर धरीऐ पाउ ॥जे ओहु देउ त ओहु भी देवा ॥कहि नामदेउ हम हरि की सेवा ॥ (Guru Granth Sahib, 525.4.1)
Translation : One stone we call god, while other one we walk on.. if the first one is god, the second one has to be god too.. Says Namdev servant of that all occupying Hari.