Protestantism or Calvinism belongs to the Reformed tradition of Protestantism. ... Today, this term also means the doctrines and practices of the Reformed churches, of which Calvin was an early leader, and the system is perhaps best known for its doctrines of predestination
https://en.wikipedia.org/wiki/Calvinism
Reformed theologians teach that sin so affects human nature that they are unable even to exercise faith in Christ by their own will. While people are said to retain will, in that they willfully sin, they are unable not to sin because of the corruption of their nature due to original sin. Reformed Christians believe that God predestined some people to be saved and others were predestined to eternal damnation