The Supernatural and the Occult
A prominent theme in the film is the supernatural and the occult. In particular, Mola Ram and the Thuggee believe in the supernatural and the occult and engage in activities related to both - from heart harvesting to human sacrifice to the forced ingestion of the Blood of Kali, a magical potion.
The magic stones also represent this theme, as they are supernatural in origin and can result in both good and bad things occurring.
Finding Hope in Difficult Situations
Despite the fact that he finds himself in an extremely difficult situation, Indy finds reason to hope for the future. Even after Mola Ram ceremoniously removes the beating heart of someone, for example, Indy still thinks that he can help the villagers 1) get their stone back and 2) get their lost children back.
Good Morals
Because Indy has good morals, he helps the villagers find their stone and missing children - something none had been able to do before. He is ultimately a good person with sound morals, something that he is at the end of the day rewarded for.
On other hand, Mola Ram and other Thuggee followers do not have good morals, which results in tremendous death and destruction to both people and the Earth.
