Most European, Iranian, and North Indian languages are related, they are all part of a group called "Indo-European". The Indo-Europeans were a powerful group that originated in the Ukrainian/Russian steppe (prairie). They had an authoritarian patriarchical society and used horses to pull their chariots. They conquered all of Europe and large parts of Asia. Whites are descended from three races: local hunter-gatherers who evolved in Europe, middle-eastern farmers, that expanded into Europe, but fairly slowly, and Indo-Europeans who conquered rapidly. These three races somewhat correspond to the 19th century types of Europeans: "Nordics" have more Indo-European ancestry, "Alpines" have more hunter-gatherer ancestry, and "Mediterraneans" have more farmer ancestry. However, all Europeans have quite a bit of ancestry for every group. Most Europeans are 99.9% descended from these three groups, but those in the border regions (south and east) have up to 10% other ancestry, such as moorish or asian. Back in the late 19th/early 20th century people were (incorrectly) using the term "Aryan" to refer to Indo-Europeans, basically as a synonym for "Nordic". As for religion, think of all the European pagan mythologies: norse, greek, etc... notice that there are similaries, such as Thor being similar to Zeus. Well that is because they all share a common Indo-European origin. Well hinduism, being an indo-european religion, also shares that origin, though it is more divergent.