Brahmanical religion failed to provide any bulwark against the attacks of the Muslim invaders. Demolition and destruction of the large number of temples all over the land by the Muslim conquerors and also the large-scale conversions shook the convictions of a section of the Hindus in the dependability of their religious beliefs. The emphatic stress of Islam on the Unity of God influenced the outlook of some reformers of the Hindu religion during this period. They advocated that the true religion consists in Bhakti or devotion to God and not in the practice of rituals. The idea of caste system was rather challenged by Islam, as they opposed to the idea of caste by birth. The Sufis who migrated to India with the Muslim traders after the conquest of India by the Muslims, spread the ideas of Islamic philosophy and mysticism through the length and breadth of India. The concept of Guru was there also in Islam it rather ideally unified with the Hindu concept of Upanishad.

The orthodoxy, deep faith and pride of the Muslims in their religion had their repercussion on the Hindus also. The Hindu rulers of Rajasthan like Rana Hamir, Kumbha, Sangram Singh and those of Vijayanagar like Krishnadeva Raya and Rama Raya displayed their velour as champions of Dharma. It was a direct outcome of India's contact with Islam that to support and safeguard Hindu religion and society and that was their main aim in life at that time.