
Kelli K. answered 11/05/19
Effective history, liberal arts, and writing coach
There is no clear cut answer to the question of what role Christianity has played in the colonization of non-European peoples. For every instance (as with the Spanish under Isabella and Ferdinand) where missionary zeal was part of the reason for embarking on exploration and imperialism, there are others where Christianity was seen as something to be avoided as troublesome, expensive, and divisive.
When the British succeeded in routing both European and Asian rivals in what is now India in the 18th century, Christian missionaries were outright banned by the English East India Company. British traders and governors, like the Mughals before them, wanted to be able to sponsor Hindu temples and schools, and this could not be done with Christian missionaries looking over their shoulder and complaining to the Crown. It was only when the Company Raj was abolished in 1858 and agents of the British Government took over direct control of the subcontinent that Christian missionaries were finally allowed to openly proselytize. As Company leaders had predicted, this did not sit well with the Indian majority population.
As for the second part of the questions, about what role indigenous religious and cultural practices played in decolonization, it is equally varied depending on time and place.To cite just one example, again from British India, one of the most fascinating aspects of proto-nationalism and nationalism proper is the syncretism that took place between non-Western and Western religious beliefs and practices. Theosophy emerged from this rich cultural stew and had an outsize influence on nationalist leaders like Gandhi, as well as European social reformers.