After 1856, Christian preachers attempting to convert Adi Dharma adherents were banned entry into Brahmo premises by Debendranath Tagore. The background to this was as follows,
In 1855, American Unitarian missionary Rev. Charles Dall arrived in Calcutta. In this year he forms the "British Indian Association" with Keshab Chandra Sen as the Secretary to the Association. Sen is the grandson of Rammohun's lifelong Hindu Sabha opponent Babu Ram Kamal Sen. In 1856 Sen organised a secret society called the "Goodwill Fraternity"[. In 1857 Keshub Sen, joins the Calcutta Brahmo Samaj when Debendranath is away meditating in the Himalayas. On his return, Debendranath instructs Dall never to enter the Brahmo Samaj or speak the name of Jesus Christ in his presence. A vengeful Dall forms the "Friends of Rammohun Society" to counter Debendranath's command over the Brahmo movement - Keshab Sen is his hand picked protege for this task.
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