Over and over again, I am impressed by the “Indian-ness” of worshipping in India. I will illustrate what I mean by this by describing a small Orthodox Christian chapel I visited on Bazaar Road in the Mattancherry district of Cochin (“Kochi”) in Kerala.
Outside the chapel, there stands a carved stone stand with indentations for oil lamps (diyas). It looks just like any diya stand that you could find in a Hindu temple, except that it is surmounted by a Christian cross.
The crucifix that stood above a small high altar within the chapel was draped with flower garlands (malas). Again, these are commonly found draped around effigies of Hindu deities.
I saw a brass diya stand with burning oil lamps directly in front of the crucifix. Like the lamp stand by the entrance, this one was also topped with a Christian cross.
If one were to replace the crucifix with an effigy of a Hindu deity and were to remove the crosses from the diya stands, the chapel would become identical to a Hindu temple.
The use of diyas and also agarbati sticks (incense sticks) is not confined to Hindu temples. I have seen them used in Christian as well as Islamic (especially Sufi) and Jain places of worship.
At a Sufi shrine at Sarkej Rauza on the edge of Ahmedabad in Gujarat, I have seen tulsi leaves being sold. These are commonly associated with Hinduism, but the vendor in the Sufi shrine told me that they were also used by worshippers who came to the shrine.
I have seen threads tied around the trunks of peepal trees by pious Hindu women hoping to have their wishes granted. I have also seen threads tied by women around pillars in Moslem shrines for the same reason.
Hinduism was probably one of the earliest religious belief systems to become evident in the Indian subcontinent. Christianity and Islam were relatively recent arrivals. Many Hindus converted to these two religions, but, I imagine, they were reluctant to abandon their Hindu heritage completely. Hence, the Hindu-ness or Indian-ness of some aspects of other religions in India.