Before we start getting to the details of Hinduism, it would be quite useful to get registered with the fact that Hinduism is quite different from the normal religion definitions and hence asks for a complete paradigm shift in terms of what is being looked for in a religion. Unless this preparation is done one is very likely to be bewildered and overwhelmed by the gigantic versatility of Hindu concepts. Many people get confused when they try to compare Hinduism with the other religions say like Christianity or Islam. While most of other religions have "well defined" boundaries, the question they have is why Hinduism is not like that. For example there would be one named God, one holy book, one founder, one set of rules, which the adherers must follow, and Hinduism does not have these kind of definitions.
This is the most important and valuable specialty of Hinduism that it has not closed itself inside any contours, but is the realistic representation of the limitlessness of knowledge and experience. It is absolutely open minded. This is the religion that calls Let the good things come from all the directions of the world (aa no bhadrAH kratavo yantu vishvataH - Rig veda). Thus this religion nurtured the good concepts with a neutral mindset. Hinduism is a dharma (discipline) than a religion. Various religions stand over this dharma. In general this is not the religion of just postulations.
Very naturally this religion does not force even the acceptance of God to the followers. The Hindus are not threatened that they would be punished for not praying/believing the God, whereas the major scriptures advice the followers to hold to the God in order to get liberated from the rough road of pleasures and pains! Even those things undergo a very healthy debate. Nothing is unquestionable. The Hindu scriptures instead of defining the way, in which the Hindus should live, in a better way, act as supporting material for the individual to decide the course of life and stand by that.
Does it mean that there is no discipline and guidance? Certainly it provides various "ready to use" paths for the simple people, but this is not a forced one for others. It would be astonishing to note that in the same platform of Hinduism both the ritualistic orthodox traditions and something like nyAya vAda, which questions and criticizes blind faith etc stay, harmoniously with meaningful discussions among them. The reason is the openness of this religion.
Hinduism is the oldest and active among all the religions that have very big number of followers. There is no definite date of birth for this religion and even in future whether it could be clearly found is not quite possible, given the fact that this discipline is found in existence even in the earliest analyzed period of the modern history. In this very big period this matured religion has contributed a lot to the humanity and developments. It is worth to stress the scientific approach and openness towards things, the proof of which lie through all its scriptures very rich in knowledge covering a large panorama, be it astronomy, mathematics, alchemy, health and personal growth and what not! The inventions and discoveries by the Hindu sages who also formulated the number system are innumerous which one finds scattered all throughout the scriptures. But it is quite shocking that the later generations, which were in politically disturbed state forgot/ ignored/ lost many of these marvels.
A unique characteristic of Hindu set of religions (includes Buddism, Jainism etc) is that its philosophers start the analysis from a more concrete and most logical question of "who am I" than to start with the postulations on an abstract God at the start. When you invent something, you probably need to have define the abstract result first and work towards that. But when it is a discovery, it should be following the known information one gets to know the unknown things beyond and finally comes the great discovery. Hinduism does not invent God but it discovers. It neither stops at the human boundary confused and failing to go forward, but gets to the divine aspects supported by facts. This makes their findings more logical and realistic and even the super human descriptions experiencable if not explainable.
These and many more specialties of Hinduism make it a harmonious and worth religion, which is suitable for any time in present or future, for any land or creed.
Whatever be the thing, whoever be the speaker, it is wise to find out the real truth in it.