Jains believe that every living being has a soul and every soul is potentially divine. They also believe in reincarnation after death. A soul can be reincarnated in any form of life. (A human being can become a worm in the next life for example). Karma is that every being determines its own fate through its thoughts, actions and deeds. Karma also plays a part in which place and form the soul takes after death. Jains also believe in the principle of ‘Live and let live’ – not just for human beings, they believe in equality of all life. I.e. however small / insignificant a being is, it has the same yearning to live as humans do and part of being a Jain is respecting its right to live peacefully.
The ‘potentially’ divine soul becomes divine when it is freed from this cycle of death and rebirth. Right faith, right knowledge and right conduct are the pathway of salvation. To free the soul from the bondage of life and death, the Jain monk follows asceticism and non-possession to the extent that a sect of Jains monks (Digambars) don’t even wear clothes. Obviously the highest form of life namely humans can practice the above and attain salvation.
There are 24 exemplary souls called as Thirthankars that have guided and revived Jainism through the ages. The most recent (24th) of them, Mahavira is historically dated to be around the 6th century BC. If you are interested in knowing who the 24 thirthankars are, Wikipedia has a nice table of the 24 Thirthankar.
Click here to know about the Digambar Jain Acharyas.
Click here to know about the Digambar Jain Literature.