The question revolves around the social reform movement of 19th century which was initiated by people like Raja Ram Mohun Roy, Ishwar Chand Vidya Sagar etc. The key words in the question are purify and rediscover. Therefore you have to base your answer on the fact that these reformers were not trying to force reforms in Indian society from European point of view but wanted to overhaul the society through rationale and informed discussion of Indian religious textbooks.
In the intro, mention the work of these reformist leaders and what were the evils present in the Indian society at that time (sati practice, prohibition on widow remarriage, infanticide etc.)
The main body should focus on how early social reformers wanted to enlight Indians that Sati, infanticide etc should be banned not because that would be conformant with the European ideals of rationalism, empiricism, monotheism and individualism but because they are not allowed in the Indian religious text. How they wanted to preserve the society while changing the behaviors of its members.
(This was the sole reason why they translated the original text into Vernacular. They knew that Indians are too religious and they can only accept these reforms when they can prove them that these practices had no basis in religious text.)