Beginning with the so-called Arab invasion of Sindh and even today (albeit in a different form), the single biggest failure of Hindus has been one or more or all of the following: inability, unwillingness, passivity, inertia, or the innate compassion that lies at the heart of Sanatana Dharma in respect of understanding the violent intolerance at the heart of the Islamic doctrine. And in the last two hundred years, Christianity. In the modern time, Hindus continue to live under subjugation of a far deeper, far sinister sort.
However, back in the 800-year period of tyrannical subjugation, the core of Sanatana Dharma was still intact. It wasn’t infected by Hindus themselves as in the present time–they will go to any lengths to call themselves anything but Hindu. On social media and elsewhere, the spectacle of such Hindus doing crazy mental, textual and intellectual contortions is truly hilarious. This fundamental wellspring of Sanatana Dharma is what enabled Hindus to evolve the Bhakti movement. This sort of response is unparalleled and perhaps can never be repeated.
A big factor of the Bhakti movement was characterized by a widespread retelling our epics and Puranas. Indeed, the Bhakti movement arose precisely due to Islam’s record of cultural homicide marked by an industrial scale destruction of Hindu temples, disallowing new ones to be built and existing ones renovated. This fact is best exemplified by the reign of Aurangzeb. Already suffering as Dhimmis (second class citizens with no rights whatsoever), Aurangzeb made it impossible for Hindus to even give expression to their deepest religious needs.
The Bhakti saints exhorted people to preserve their way of life and worship in whatever form–nothing was taboo. A big component of Bhakti saints comprised saints, poets, and singers who wandered across India exhorting Hindus to preserve their time-tested ways of life, tradition and life. They worshipped Hindu Gods and Goddess in songs composed in simple and/or rustic lyric in the local language that was easy to memorize and recall, and could be set to tune. The beauty and spontaneity of the Bhakti movement was that it transcended geography by being decentralized, it became that much harder to contain it with violence. As Hari Ravikumar says in an article dispelling myths and mischaracterizations of the Bhakti movement,
When we see the great bhakti poets – be it Shankar Dev of Assam, Narsinh Mehta of Gujarat, Meera of Rajasthan, Ravidas of Uttar Pradesh, Akka Mahadevi of Karnataka, Tukaram of Maharashtra, or Auvaiyar of Tamil Nadu – we find that they hail from all classes of society and from varied backgrounds.
Urilingapeddi was a Dalit, Basavanna was a Brahamin. Jnaneshwar was a Brahmin, Tukaram was a Shudra. Tiruppanalvar was a Dalit, Kulashekharalvar was a Kshatriya, Nammalvar was a Shudra. Purandaradasa was a Vaishya, Kanakadasa was a Shudra.
Thus, when the Ramayana or stories from our Puranas could no longer be recited or performed openly under an oppressive Islamic state, the Bhakti saints made them immediately accessible, by making Rama one’s neighbor, while Krishna was just waiting on the other side of the river. These saints drew parallels, analogies, and illustrations from everyday life, which helped retain Sanatana Dharma as a living and lived tradition. The Bhakti movement also simultaneously instilled great psychological courage among the masses of battered Hindus whose Gods were trampled upon and their murtis (incorrectly translated as “idols”) mutilated and destroyed.
Centuries of such sustained efforts eventually led to a great pushback: the rise and rise of the legendary Shivaji who successfully defied Aurangzeb and laid the foundation for the later expansive and mighty Maratha Empire is a shining illustration of this fact. The fact that his life and contributions were inspired by his spiritual Guru, the Bhakti-Philosopher saint Samartha Ramadas, and Sant Tukaram who received a high place of honour is an additional testimony to the rejuvenating powers of the Bhakti movement.
After the fall of the Mughal Empire and with the eventual takeover of India by the East India Company, the 19th Century witnessed the unprovoked attack by Christianity against Sanatana Dharma. Conversions of Hindus into Christianity was an accepted organ of the British imperial policy. It was indeed a renewed attack: as the scholar-historian R.C. Majumdar says, the British takeover of India was an event during which India merely changed masters.
The attack that Christianity launched against Sanatana Dharma was sophisticated but equally brutal and far reaching in its consequences. India is yet to recover from the damage it has wrought. In the early days, when Christian missionaries failed to persuade Hindus to convert through various devices and sustained efforts, it re-clothed its message and equated its Messianic preaching with whatever parallel it found in Sanatana Dharma. In effect, it claimed that Christianity was no different from Santana Dharma–only the Gods and saints were different. The story of how the “Roman Brahmin” (sic) Roberto De Nobili wore a “Christian sacred thread” to imitate Brahmins as a ploy to convert Hindus is a case study in point. When all his arduous efforts came to naught, he suddenly turned against Brahmins and began to vilify them.
Initially, significant numbers of “upper caste” Hindus converted, most notably in Bengal. However, the gains were insignificant because almost in no time, the Hindu response was swift. A strong tide of Hindu resurgence led by the likes of Swami Dayananda Saraswathi and Swami Vivekananda pretty much scuttled such conversion attempts. The Church then realized that it could not win converts if it challenged Sanatana Dharma purely on philosophical grounds. That was when missionaries targeted the poorer sections of Hindu society, a tactic that remains unchanged till date.
However, the greatest damage that British rule did to India was to carve out what is now infamously known as the Macaulayite class of Indians. Needless, majority of this Macaulayite class are upper caste Hindus. Our Marxists, secularists and liberals are the descendants of the worst of this Macaulayite class. To their credit, creating this class was perhaps the greatest accomplishment of the British, something that the eight-hundred-year-long Islamic rule couldn’t accomplish by force: pitting Hindus against each other by making them ashamed of their own identity.
It is also well-known that the project of Macaulayizing Hindus began with the imposition of English education. While at one level, it did open up new vistas in the areas of science, technology, and Western ideas of freedom, liberty, democracy, nation and state, the accompanying cultural destruction it brought about is a blow that India seems unable to recover from.
In the early stages of this project, Swami Vivekananda stood as the foremost counter by his tireless efforts to reawaken Hindus to their own past glory. Needless, he continues to remain a great source of inspiration. His efforts were followed by a whole galaxy of Indian scholars who began investigating different aspects of their past and publicizing their findings to the world. On the political front, we had freedom fighters who found inspiration in Sanatana Dharma’s epics, scriptures, saints, and warriors. Indeed, the timeline roughly encompassing the mid-nineteenth to the mid-twentieth century can be considered the period of modern Indian Renaissance.
 Mint article on bhakti movement reeks of ignorance about Indian culture: Hari Ravikumar, DailyO, 14 November 2016
 Chapter 3: The Patron Saint of Indigenisation: Catholic Ashrams: Sita Ram Goel, Voice of India, 1994