Arjuna is upset about going into battle in the Bhagavad Gita because he is facing his own family members and friends on the opposing side. He is also afraid of what will happen if he wins the battle. His charioteer, who is revealed to be the god Krishna, responds to Arjuna's doubts and fears by reminding him of his duty as a warrior and his obligation to fight for the right cause. Krishna also tells Arjuna that he will be victorious in the battle, no matter the outcome.
In Hinduism, karma is the law of cause and effect which states that the actions one takes will have consequences. Dharma is the moral law of the universe that governs the behaviors and duties of individuals. Reincarnation is the belief that a person's soul will be reborn in another body after death.
Both Hinduism and other spiritual beliefs from Mesopotamia, Egypt, and China share elements such as the belief in an afterlife, the concept of karma, and the notion of divine justice. Key differences include the different gods or deities worshipped in each religion, the religious texts each belief system follows, and the rituals and practices used in each faith. Buddhism in particular does not believe in the concept of a god, instead emphasizing the importance of personal spiritual development and enlightenment.