In India, we start all our activities by invoking Lord Ganesha, who has a form, shape, and a symbol, but in spite of all the symbols, the scriptures refer to Ganesha in the Ganesha Stavam as :
Ajam nirvikalpam niraakaaramekam
Niraanandam aanandam advaita poornam
Param nirgunam nirvishesham nireeham
Para brahma roopam Ganesham bhajema.
So when you bow down to Ganesha, think that you are bowing down to the manifestation of that Para Brahman, the Supreme.