Hinduism is not a polytheistic religion. Defining text of Hindu religion is not Shrimad Bhagvad Geeta.
Ghaznis plundered Somnaths. Some unscrupulous Hindus continue to steal funds of temples like Shri Ram Janmabhoomi and others. Reason?
The only Supreme Being doesn't control or interfere in anyone's lives or worldly events. All get Fal - results, solely as per their Karm - deeds. Idols and temples are for Dhyan.
Know the real Sanatan Dharm in the context of correct and simple understanding of the scriptures and in comparison with the other major religions. Read the easy-to-understand summaries of the main texts of the major religions.
Sanatan Satya - The Eternal Truth is an absorbing tale with Shankaracharya tradition - which many believe to have continued for about 2000 years, acting as a common thread. It is an absolutely essential read for non Hindus to understand Hinduism; and for Hindus to practice their Dharm with clear understanding and conscience.