Calvinism is the Christian theology of John Calvin, a French church reformer. Calvinists, or so believers of Calvinism are called, believe that humans have no free will because of the Fall of Adam, but are already chosen to salvation or totally rejected by God eternally to Hell. Calvinists also believe that the Bible is the unique rule of faith, and that the Church should be separate from the state. Calvin said that thrift, industry, and hard work were forms of moral virtue. His belief that business success was a sign of God's grace, helped end feudalism and establish capitalism.
Calvinists believe in five main thoughts--total depravity, unconditional election, limited atonement, irresistible grace, and perseverance of the saints. Total depravity is the tenet that sin has been extended through the whole human body. Because humans are totally filled with sin, they are incapable of the message of the Bible. Unconditional election is the thought that God has already chosen people to be with him in Heaven.
It says that no matter what people do, they cannot change God's decision. Limited atonement states that Christ died only to save those who believe in Him. Those who believe in Him call themselves Christians. Calvinists believe that in salvation, everyone shall come to know the knowledge of Him. This is called irresistible grace. Perseverance of saints is the belief that all of whom God has saved will "remain in God's hand until they are glorified with Him in Heaven".
Calvinism started to become adopted by the early 17th century. Protestant groups were the first to accept the religion. In this period many Calvinistic movements were formed, the Huguenot movement being one of them. Most Calvinistic converters, however, were Protestants. Even today Calvinism is a mild threat to the Protestant religion.