Reddit reviews Do The Gods Wear Capes?: Spirituality, Fantasy, and Superheroes (New Directions in Religion and Literature)

Yes. The Bhagavad Gita is a chapter in the Mahabaratha. It takes place immediately before a major battle. It is such a pivotal moment in the story though that it has been studied and expounded upon heavily, so it might be worth it to get a separate unabridged version. It uses some of its impact of you don't have all the context of the larger story going in though.

The theory is that it was added into the work as a later addition to sort of summarize the ethical and philosophical aims of the religion.

The epics are definitely worth reading in full though. I'd save the comics for the ancillary myths and stories. The comics are also a little Western influenced and aimed at children so they gloss over a lot of the darker themes of violence and sexuality present in some myths, particularly about Kali.

As for the comic-book nature I think you might have the relationship backwards. It is human nature to yearn for these sorts of larger than life symbols and moral ideals. So in a culture without a strong tradition of native mythology, comic books took form to fill that void. (None of these are original thoughts of mine BTW).