Jainism had taken birth against Brahmanic supremacy. It had taken initiatives to free the people from expenditures of Yagnas. It preached non-violence which let third sections of people in ancient India evolve. People were attracted to Jina principles.
Difference between Jainism and Hinduism:
1. Jainism questioned the Vedas and existence of God.
2. Jainism stressed on Non-violence (That is why Jain colleges do not have Bi.P.C. group), whereas Hinduism was based on sacrifices.
3. The salvation depiction is also different. According to Jainism, after death, one lives in blissful abode, whereas in Hinduism, each soul will be absorbed into God.
Similarities between Jainism and Hinduism:
1. The theory of karma is same regarding these two religions.
2. Transmigration of souls is also considered same.
3. Jainism asceticism is indebted to Hinduism asceticism.
Why was Jainism considered as Hinduism?
Due to similarities, Jainism could not maintain its distance. The religion which was raised against Brahmanic supremacy had relaxed after being shown leniency. As Jains were from Hindus, simply began to be considered as Hindus. Now Buddhism and Jainism are regarded as Hinduism.