Protestantism originated in the 16th century Protestant Reformation. Protestant doctrine, also known in continental European traditions as Evangelical doctrine, is in opposition to that of Roman Catholicism. It typically holds that Scripture (rather than tradition or ecclesiastic interpretation of Scripture) is the source of revealed truth.
Meaning and origin of the term
The word Protestant is derived from the Latin protestari  meaning publicly declare which refers to the letter of protestation by Lutheran princes against the decision of the Diet of Speyer in 1529, which reaffirmed the edict of the Diet of Worms in 1521, banning Luther's documents. Since that time, the term Protestantism has been used in many different senses, often as a general term merely to signify that they are not Roman Catholics.
While churches which historically emerged directly or indirectly from the Protestant Reformation generally constitute traditional Protestantism, in common usage the term is often used to refer to any Christian church other than the Roman Catholic Church and the Eastern Orthodox Churches. This usage is imprecise, however, as there are non-Roman Catholic and non-Eastern Orthodox churches which predate the Reformation (notably Oriental Orthodoxy). The Anglican tradition, although historically influenced by the Protestant Reformation in what is called the English Reformation, differs from many Reformation principles and understands itself to be a middle path—a via media—between Roman Catholic and Protestant doctrines. Other groups, such as the Mormons and Jehovah's Witnesses, reject traditional Protestantism as another deviation from Christianity, while perceiving themselves to be restorationists.
The three fundamental principles of traditional Protestantism are the following:
Supremacy of the Bible
The belief in the Bible as the sole infallible authority.
Justification by Faith Alone
The subjective principle of the Reformation is justification by faith alone, or, rather, by free grace through faith operative in good works. It has reference to the personal appropriation of the Christian salvation, and aims to give all glory to Christ, by declaring that the sinner is justified before God (i.e. is acquitted of guilt, and declared righteous) solely on the ground of the all-sufficient merits of Christ as apprehended by a living faith, in opposition to the theory — then prevalent, and substantially sanctioned by the Council of Trent — which makes faith and good works co-ordinate sources of justification, laying the chief stress upon works. Protestantism does not depreciate good works; but it denies their value as sources or conditions of justification, and insists on them as the necessary fruits of faith, and evidence of justification.
Universal Priesthood of Believers
The universal priesthood of believers implies the right and duty of the Christian laity not only to read the Bible in the...