Are the Ancient Greek and Indian Religions Interchangable?

Commenter BC seems to think so:

The classical Greek system and the vedic system are totally interchangeable. They have the same metaphysics, and applying those very same metaphysics to the Germanic myths unlocks their meaning and make them sing like birds. So there is definitely a shared metaphysics. I personally reject the term religion, since I strongly feel that only prophetic "religions" are religions. Those that require blind faith in a sacred book.

As a heathen, the world itself is my "book", the place where I am standing is sacred ground.

[But] To actually do this, requires good metaphysics. Using the symbols and myths for their explanatory power, and not relying on them as factual accounts. Unfortunately, metaphysics is hard, so many people skip this step

I would say that it's certainly accurate that very similar philosophical schools emerged under the respective umbrellas of both Hinduism and Classical Hellenism. And of course, there are striking similarities in the early/archaic form of both of these mytho-cultural worldviews. And finally, it's undeniable that both share a common Indo-European source; though of course both diverged quite a bit in terms of specific mythological content, and to a lesser degree, symbolic associations.

And on the term "religion" itself, well...that's up for debate (an endless one), but I can say that "religion" today is a term loaded with all sort of prophetic and monotheistic connotations. In the old days, when every culture was a dharma culture, spiritual practice/being was simply The Way.

Prophetic Religions vs. Natural Religions

JMG on the distinction between these two approaches to religion:

"Very broadly speaking, there are two categories of religions, which we can call natural religions and prophetic religions. (Prophetic religions like to call this latter category "revealed religions.") A natural religion grows out of the religious experience of a people over time. A prophetic religion is invented by an individual (the prophet) who rejects the religious experience of his people and insists that people should follow his rules instead. Natural religions are pretty much always polytheist. Prophetic religions are more often monotheist, though of course there are exceptions. Clear so far?...

My take, for what it's worth, is that prophetic religions are always contaminated by the ego of the prophet, who says in effect, "My religious experience is better than your religious experience, and my god is better than your god."

Monotheism is the extreme expression of that ego trip: "There's only one god and he's mine, mine, mine!" It's one of the distinctive features of prophetic religions that they insist that a scripture written by the prophet or his disciples takes precedence over everyone else's ongoing experience of deities. Thus it doesn't matter, to believers in a prophetic religion, what the god does or doesn't say; what matters is what the prophet said about the god. (And of course "Our scripture is better than your scripture" is another dimension of the ego trip.)

The gods of monotheist religions seem to be far more tolerant than most of their worshipers. I know a lot of people, for example, who combine reverence for Christ with reverence for other gods and goddesses, and their experience is that Christ doesn't mind this at all -- however many fits his self-proclaimed spokespersons might throw over such a thing. Thus it seems likely to me that Christ, for example, is one god out of many, who had the misfortune of having some of his followers go zooming off on an ego trip of the sort just described."

One little caveat/clarification I feel the need to add to the very insightful remarks above; that the Natural Religions of great civilizations and high cultures usually ended up including a plethora of different philosophical theories and approaches, such as Panentheism, Monism, Pantheism, ect., not just "Hard Polytheism."