The Cult of Trināth
Roy's account informs us that in the early part of the twentieth century the worship of a new god called Trināth emerged in certain parts of Orissa. Trināth was supposed to embody Brahmā, Viṣṇu, and Śiva. His worship was very simple, affordable, and there was no necessity of a family priest to officiate. The implements were bought with three paisa and three paisa only: one for some oil, one for some betel leaves, and one for a small amount of cannabis.
The cult, although only fifteen years in the becoming, already had a lengthy scripture (called the Trināth Charita Akhan) with stories of Trināth with marked emphasis on the misfortunes of those who refused to worship him and the returned favours for those who eventually gave in. This article basically gives us two important factors for the emergence of a new cult:
1. The new cult should not be too new, but ought to recycle something from the older traditions. (here: Trināth embodies the three major gods)
2. It ought to have an attractive social agenda. (here: giving the option to exclude the family priest and the affordability of the pūjā implements)
This is most likely not a special and isolated case. Hence, perhaps we should reconsider the unfounded idea that a scripture has to acquire 'vintage' (estimated by some to centuries) before the exegetes come around.
UPDATE: it seems that Roy was slightly misinformed about the dates. There is a report of Trināth worship from as early as 1867. Read here.