There are two meanings of the phrase sanatan dharma. One is political, and the other philosophical.

The political sanatan dharma emerged as one of the two responses to European Orientalists who saw Hinduism as a pagan, polytheistic and idolatrous race. One response, the Samaj response, was to reform prevalent Hindu customs and beliefs and make it worthy of colonial approval. So emerged many organisations that rejected worship of plants, animals, rocks and images and saw God in formless monotheistic terms. These reformers focused on prayer and prayer halls, creating something like a ‘Hindu church’.