Early political life of Raja Ram Mohan had immense impact on modern Indian history. It actually led to the complete revival of ethical principle of Vedanta school of philosophy as found in Upanishads. He preached about the oneness of God and also made translation of Vedic scriptures into English and co-founded Calcutta Unitarian Society - founded the Brahmo Samaj and also campaigned against Sati. He also sought to integrate Western culture with features of Indian traditions. He also set up schools to modernize education in India.
During this period he also worked as political agitator and agent while also being employed by British East India Company and simultaneously pursuing his vocation as a Pandit. In the years spanning from 1796 and 1797 the troika of Carey, Vidyavagish and Roy made-up a bogus religious work known as the Maha Nirvana Tantra (or "Book of the Great Liberation") and tried to depict it as an antique religious manuscript to "the One True God". The judicial section of the document was used in the law courts of the English settlements in Bengal as Hindu Law for adjudicating upon property disputes of zamindari. However, British magistrates and collectors began to suspect it as forgery and its usage as well as the dependence on pundits as sources of Hindu Law was quickly denounced. Vidyavagish had a nasty fall-out with Carey and separated from the group but also maintained ties to Ram Mohan. The importance of Maha Nirvana Tantra for Brahmoism lay in the riches that accumulated to Dwarkanath Tagore and Ram Mohan Roy by its judicial use, and not due to any religious wisdom within.
In 1799, Carey was joined by missionary Joshua Marshman and the printer William Ward at the Danish settlement of Serampore. From 1803 to 1815 Ram Mohan worked in the British East India Company and provided writing service, commencing as private clerk "munshi" to Thomas Woodforde, Registrar of the Appellate Court at Murshidabad, whose distant nephew, also a Magistrate, later made a living off the spurious Maha Nirvana Tantra under the pseudonym Arthur Avalon.
Raja Ram Mohan Roy, in 1815 formed "Atmiya Sabhan", and spent many years at Rangpur and elsewhere with Digby, where he renewed his contacts with Hariharananda. William Carey had, by this time, settled at Serampore and the trio renewed their association with one another.
British East India Company was extracting money from India at a very high rate (about three million pounds a year) in 1838. Raja Ram Mohan Roy estimated how much money is laundered with and what is the exact amount that is driven out of the country. He also predicted that around half of the total revenue collected in India was sent out to England, leaving India to fill taxes with the remaining money.
In the beginning of 19th century, after the Battle of Plassey and Buxar (population of the Muslim community decreased considerably) posed a political threat to the Company. Ram Mohan was now chosen by Carey to be the agitator among them. In the next two decade, after Carey`s secrete tutelage, Ram Mohan started his attack against the citadels of Hinduism of Bengal, namely his own Kulin Brahmin priestly clan (then in control of the many temples of Bengal) and their priestly excesses. The theological and social issues Carey chose for Ram Mohan were also calculated to weaken the hold of dominant Kulin class most importantly for younger disinherited sons forced into service who formed the mobile gentry or "bhadralok" of Bengal, from the Mughal zamindari system and align them to their new overlords of Company. The Kulin excesses targeted included child marriage and dowry. In fact, Carey tried to convert Raja to Christianity and appointed a religious priest to try to convert Raja, although the priest later accepted Hinduism.
