Proto-Protestantism, also called pre-Protestantism, refers to individuals and movements that propagated various ideas later associated with Protestantism before 1517, which historians usually regard as the starting year for the Reformation era. The relationship between medieval sects and Protestantism is an issue that has been debated by historians.
Overview
Before Martin Luther and John Calvin, some leaders tried to reform Christianity. The main forerunners of the Protestant Reformation were Peter Waldo, John Wycliffe and Jan Hus. Martin Luther himself saw it important to have forerunners of his views, and thus he praised people like Girolamo Savonarola, Lorenzo Valla, Wessel Gansfort and other groups as prefiguring some of his views.
Claimed to have prefigured Protestantism
John Foxe (c. 1563) was the first English Protestant author to defend Protestantism from charges of novelty by claiming, in S.J. Barnett's words, "the continuity of a proto-Protestant piety since apostolic times": in England's case this included a national conversion to Christianity from a visiting Joseph of Arimathea.
According to Edmund Hamer Broadbent in The Pilgrim Church, over much of the Christian era, many Christian sects, cults and movements foreshadowed the teachings of what later became the Protestant movements.
Movements that have been argued as having similar individual ideas as Protestantism before the Reformation are:
Antidicomarians: Antidicomarians refused to give Mary "special status" and denied her perpetual virginity, their positions on Mary became the standard in many Protestant sects. Aerius of Sebaste: Aerius of Sebaste is seen as a forerunner of the reformation by some Protestants, he attacked monasticism, denied fasting commandments and denied the episcopal polity. Helvedius: Helvedius is seen by some Protestants as a forerunner of the reformation, Helvedius opposed the doctrine of the perpetual virginity of Mary and monasticism, he was attacked by Jerome. Jovinian and Jovinianism (died ): Jovinian was a 4th-century theologian who challenged the wave of ascetism in the 4th century, challenged the exaltation of virginity, denied the perpetual virginity of Mary, and he believed that there is no difference between abstaining from food and enjoying it with thanksgiving. Jovinian taught a perseverance doctrine similar to John Calvin, as he taught the truly regenerate will persevere to the end. Some also have argued Jovinian held grace oriented salvation views, similar to the Reformation. Jovinian is sometimes praised as an early forerunner of the reformation. It has been argued that Jovinian believed in a distinction between the visible and invisible churches, based on his statement that the Church is founded on faith, and that all in the Church are taught by God and that no "unripe" members exist within the Church and no one can enter the church "by fraud".