Interaction with other religions
Since Hinduism never existed as a monolithic religion, but lived in parts and in numerous guises, the competing religions which either originated in india or entered indian from outside during its long history could not make much difference to it. They influenced it in parts, while they were influenced in turn, thus resulting in a synthetic ethnic culture which currently distinguishes the indian subcontinent from the rest of the world. The interaction also resulted in numerous reforms and improvements within Hinduism. For example, hindu caste system grew from a fourfold system into a complex system consisting of numerous castes and sub castes. Secondly it shifted the attention of its followers from external ritual practices to internal spiritual practices. Thirdly it facilitated the integration of numerous schools. We can see traces of early reforms within Hinduism in the epic Mahabharata, several Upanishads and the bhagavad gita. We may reckon lord Krishna as one of the earliest social and religious reformer of his times. The Buddha was not the first social or religious reformer of ancient india. Before him there were many and among them lord Krishna was one of the most prominent. To a careful reader of the bhagavad gita it becomes self evident that the scripture was a reaction against religious conditions of his times. It synthesized many divergent ideas and created a coherent philosophy and spiritual approach to the problem of bondage and karma, and the ideal solutions to achieve liberation. It presented a rational basis to the people to resolve the contradictions that were inherent in the paths of actions (karma), knowledge (jnana), intelligence (buddhi), renunciation (sanyasi), contemplation (atma samayama), and devotion (bhakti), the path of knowledge, and put them together to achieve the four chief aims of human life namely dharma, artha (wealth), kama (sexual desire) and moksha (liberation). The divergent darshana philosophies of Hinduism, and the emergence of atheistic or renunciant traditions such as the carbakas, apart from the rise of Buddhism and Jainism, the lokayatas, parivrajakas, ajivikas and nirgaranthas were also products of a similar development. Although they opposed it and competed with it for followers in the end they either yielded to its influence or became dissolved in it. The Upanishads, the end part of the vedas, were also products of scholarly reaction against the tyranny of the vedic ritualism sanctioned by the samhitas and brahmanas. Similar was the case with the bhakti movement, which originally started in the south in the first or the second century AD, and culminated in the subsequent rise and popularity of Saivism and Vaishnavism. The rise of the tantrism and other movements, at a time when Buddhism and Jainism were on the ascendance and gaining ground, added complexity and depth to the ancient indian religious thought and provided it with the much needed diversity for which it is famous today. The schools of monism (advaita), dualism ( dualism) and qualified dualism (vishishtadvaita) were the internal reactions, which attracted the attention of many seekers of truth and encouraged them to explore the true nature of the reality of the world in which they lived. It is said that competition amongst these divergent sampradayas (traditions) was very intense, sometimes resulting in religious intolerance, infrequent wars and quarrels, religious debate and mutual abuse. However, through that commotion and confrontation the vedic religion somehow emerged as a complex tradition, gaining depth and complexity from numerous sources. It is still the most dominant tradition of india, which wields considerable influence over large sections of society.
Hinduism encounter with islam and Christianity
Interaction with other religions, coupled with internal reforms and assimilation of numerous sects and traditions, and absence of a distinct identity or monolithic character, helped Hinduism successfully cope with islam and Christianity when they entered the subcontinent through foreign subjugation. When they confronted the native faiths, the two religions had immense political patronage and vast resources to exert themselves. However, they succeeded but little largely because what they dealt with was largely unlike them in organization as well as essential character. Hinduism, then was not yet a recognized, unified religion. It existed but in name. what they confronted was a large body of distant traditions and practices and a native population of diverse ethnic, social, political, linguistic, regional groups. The very flexibility of the native traditions, the loyalty, devotion and commitment of the native people to their beliefs and practices, despite the absence of centralized religious authority, were the major obstacles which they were unable to overcome. Therefore, they succeeded but little. With the help of money, power and political coercion, they managed to convert a few groups, but largely they remained ineffective. They did shake Hinduism and left it a little bruised and battered in parts, largely they were unsuccessful to change the native mindset and the loyalty of the people to their ancestral religions.
Folk traditions of Hinduism
Since the earliest times, india has been home to a diverse group of people. It is now widely believed that the indus valley people were heterogeneous and belonged to diverse racial and ethnic groups. The diversity of indian population remained intact throughout its long history. Vedic community itself was not much different form the rest of india. Apart from urban settlements and organized village communities, there were many tribes and rural folk who lived in different parts of the subcontinent, practicing various faiths and occupations and speaking numerous languages. Most of them lived on the fringes and vedic society and the civilized world, but enjoyed considerable freedom in practicing their faith. They had no access to the vedic scriptures or right to worship the vedic gods. Instead, they worshipped nature, plants, trees, mountains, rivers, ancestors, sprits, snakes, lakes, oceans, and so on. At times, they also practiced animal and human sacrifices. Today some of their practices have become integrated into Hinduism. In many parts of india people still worship village and local deities, celebrate festivals in their honor, make offerings to the ancient sprits. Thus we can see that what we today understand as Hinduism originally started thousands of years ago, and overtime absorbed numerous traditions, beliefs and practices, acquiring in the process a great complexity, depth and character, and catering to the religious and spiritual needs of the educated and enlightened as well as the ignorant and the uninformed.