As far as the question of the soul is concerned among those who subscribe to Hinduism, Jainism, Buddhism and Sikhism, there are a few areas of agreement as well as contentions, which I will explain in a nutshell. In Hinduism, the soul exists beyond the physical body, and that it goes through a series of reincarnations until it becomes perfect and reunites with its source (p.98). The soul therefore enters different bodies, as it is not contained in one body, and goes through a number of deaths and rebirths. The period of the stay of the soul in between the cycles is dependent upon the sins committed by the physical self and how much one strives to overcome such sin.
In Jainism, the soul is the conscious substance present in all living organisms. All matters of knowledge, sense and perception are within the confines of the soul. They believe that the soul is eternal but undergoes a number of changes, each soul is an independent entity and has no relationship with any god, and like Hinduism, when the body dies, and the body migrates to another body and undergoes the cycle of reincarnation until when one’s ethical life is until nothing remains but purity (p.121). They also believe that each soul is responsible for its sins. They also believe that there are two types of souls, the liberated ones and those bound in sins, and that the number of souls is infinite, in the sense that they neither increase nor decrease as they cannot be created or destroyed.
Buddhists do not believe in the soul theory, but instead have their own Annata doctrine. They consider the soul theory baseless and illusionary, claiming that it is a combination of physical and mental forces, made up of body or matter. They believe that these forces form energies which are what they call the soul. They do not believe in reincarnation, but they are of the view that when the physical body dies, these energies do not die, hence a rebirth can happen and the soul continues to live in a form that changes every moment (p.140).
According to Sikhism, the soul is what gives life to the physical body. Upon its exit, the physical body becomes lifeless. The soul drives the body and is non material. They call the spark which keeps the physical body alive. The Hindus and the rest differ when the debate of the caste system is brought up. While the Hindus believe that the Vedas were divinely ordained (p.114), and cannot be challenged, the rest feel that anybody, irrespective of whether born in poverty has the ability to build on their knowledge and rise to any status they like.
References
Mary Pat Fisher, Robin Rinehart. Living Religions. 10th Edition