Calvinist theology refers to the doctrines of John Calvin, a 16th-century Christian reformer. Modern churches that hold to Calvinist theology include Orthodox Presbyterians, Reformed Presbyterians and some Baptist groups, among others. The basic doctrines of this belief system, formalized by the Synod of Dordt in 1619, are "total depravity, unconditional election, limited atonement, irresistible grace, and perseverance of salvation" (TULIP). Various groups may take a various approach to the five-point model of Calvinism, but the overarching ideas are reasonably consistent and lead to other doctrinal and cultural similarities among Calvinist denominations.
Total depravity, within Calvinist theology, is the belief that humans are inherently sinful from birth and that all human efforts toward improving themselves are basically ineffective. This view is similar to Catholic teachings about original sin, but contrasts humanist Christian theological beliefs that humans are able to better themselves. Unconditional election is the view that God elects individuals to be saved based on his own choice rather than on their merits, since according to the doctrine of total depravity humans do not have merit. Those not predestined for salvation, in most Calvinist views, are predestined for hell.
Limited atonement means that Christ's atonement covers only the sins of the elect, not of all people. Contrasting theologies, such as Armenianism, may argue that the atonement was on behalf of all people and that a person's choice to accept or refuse the atonement is what determines whether his or her sins are forgiven. In Calvinist theology, however, a person does not make a choice about whether to be saved, but is drawn to salvation by God's irresistible grace, which is the fourth of the five points of Calvinism.
According to Calvinist theology, because God chooses the elect, he also provides them with strength to persevere in their faith. This doctrine is known as the perseverance of salvation or perseverance of the saints. Those who follow this doctrine believe that a member of the elect cannot lose his or her salvation by turning away from faith, and a person who appears to do so is proved not to have actually been one of the elect.
Calvinist theology is often perceived as a very dark theology due to its emphasis on human depravity and its view that those who are not elect are predestined for hell. Historically, Calvinists have tended to have strict moral codes. The Puritans, for instance, were an English Calvinist group in the 16th and 17th centuries known for their disapproval of Christmas celebrations and the theater, among other things. On the other hand, early American Puritans are sometimes more positively remembered for their individualism and comparatively egalitarian social structures.