When writing in English on Rabindranath Tagore's thoughts on religion, most scholars prefer to focus on his 1930 Hibbert lectures at Oxford, published as The Religion of Man. His second major work on religion, Mānusher dharma, the Kamal Lectures at Calcutta University (1933), is an expansion rather than merely a translation of the former as its synonymous title might be taken to imply. The poet's ideas on the religion of humanity did not come to a standstill at this point: he continued to develop his ideas through the rest of his life. Some scholars even believe that he ultimately became an atheist, having arrived at a human-centric ‘religion of Man’ towards the end of his life. Others think his position can be interpreted either for or against atheism. There were shifts in his position both before and after the Hibbert lectures. He was constantly engaging with new ideas and insights across an expanding horizon of lived experience. All of this was factored into his religious sensibility without any break in continuity.

When the Brahmo Samaj, known as a neo-Vedantic institution, split into the Ādi Brahmo Samaj and the Bhāratvarshiya Brahmo Samaj in 1866, Rabindranath was five years old. His father Debendranāth Tagore led the Adi Brahmo Samaj. This group claimed that they were Hindus and that their reading of the Vedas was the authentic one, unlike the convoluted interpretation of orthodox practising Hindus of that period. Debendranath contributed to the development of a monotheistic religion based on the philosophy of the Upanishads. Rabindranath was initiated to the Upanishadic teachings by his father at an early age: he actively participated in all the religious activities conducted by his father at the Samāj. In 1884, at the age of twenty-three, he was appointed secretary of the Adi Brahmo Samaj. This started the first phase of his public engagement with religion. During this period his thoughts were traditional, with hardly any trace of individuality.

As secretary of the Adi Brahmo Samaj, Rabindranath was drawn into various debates of the time. A major debate took place with Bankimchandra Chattopādhyāy (Chatterjee), the leading novelist, thinker, and public intellectual of the day. Bankimchandra argued that truth is related to the welfare of the people. What is not conducive to the welfare of the people is false, even though it may outwardly appear to be true.