Origin of the name
The Diet of the Holy Roman Empire, assembled at Speyer in April, 1529, resolved that, according to a decree promulgated at the Diet of Worms (1521), communities in which the new religion was so far established that it could not without great trouble be altered should be free to maintain it, but until the meeting of the council they should introduce no further innovations in religion, and should not forbid the Mass, or hinder Catholics from assisting thereat.
Against this decree, and especially against the last article, the adherents of the new Evangel the Elector Frederick of Saxony, the Landgrave of Hesse, the Margrave Albert of Brandenburg, the Dukes of Lüneburg, the Prince of Anhalt, together with the deputies of fourteen of the free and imperial cities entered a solemn protest as unjust and impious. The meaning of the protest was that the dissentients did not intend to tolerate Catholicism within their borders. On that account they were called Protestants.
In course of time the original connotation of "no toleration for Catholics" was lost sight of, and the term is now applied to, and accepted by, members of those Western Churches and sects which, in the sixteenth century, were set up by the Reformers in direct opposition to the Catholic Church. The same man may call himself Protestant or Reformed: the term Protestant lays more stress on antagonism to Rome; the term Reformed emphasizes adherence to any of the Reformers. Where religious indifference is prevalent, many will say they are Protestants, merely to signify that they are not Catholics. In some such vague, negative sense, the word stands in the new formula of the Declaration of Faith to be made by the King of England at his coronation; viz.: "I declare that I am a faithful Protestant". During the debates in Parliament it was observed that the proposed formula effectively debarred Catholics from the throne, whilst it committed the king to no particular creed, as no man knows what the creed of a faithful Protestant is or should be.
Characteristic Protestant principles
However vague and indefinite the creed of individual Protestants may be, it always rests on a few standard rules, or principles, bearing on the Sources of faith, the means of justification, and the constitution of the Church. An acknowledged Protestant authority, Philip Schaff (in "The New Schaff-Herzog Encyclopedia of Religious Knowledge", s.v. Reformation), sums up the principles of Protestantism in the following words:
The Protestant goes directly to the Word of God for instruction, and to the throne of grace in his devotions; whilst the pious Roman Catholic consults the teaching of his church, and prefers to offer his prayers through the medium of the Virgin Mary and the saints.
From this general principle of Evangelical freedom, and direct individual relationship of the believer to Christ, proceed the three fundamental doctrines of Protestantism the absolute supremacy of (1) the Word, and of (2) the grace of Christ, and (3) the general priesthood of believers. . . .
Sola scriptura ("Bible alone")
The [first] objective [or formal] principle proclaims the canonical Scriptures, especially the New Testament, to be the only infallible source and rule of faith and practice, and asserts the right of private interpretation of the same, in distinction from the Roman Catholic view, which declares the Bible and tradition to be co-ordinate sources and rule of faith, and makes tradition, especially the decrees of popes and councils, the only legitimate and infallible interpreter of the Bible. In its extreme form Chillingworth expressed this principle of the Reformation in the well-known formula, "The Bible, the whole Bible, and nothing but the Bible, is the religion of Protestants." Protestantism, however, by no means despises or rejects church authority as such, but only subordinates it to, and measures its value by, the Bible, and believes in a progressive interpretation of the Bible through the expanding and deepening consciousness of Christendom. Hence, besides having its own symbols or standards of public doctrine, it retained all the articles of the ancient creeds and a large amount of disciplinary and ritual tradition, and rejected only those doctrines and ceremonies for which no clear warrant was found in the Bible and which seemed to contradict its letter or spirit. The Calvinistic branches of Protestantism went farther in their antagonism to the received traditions than the Lutheran and the Anglican; but all united in rejecting the authority of the pope. [Melanchthon for a while was willing to concede this, but only jure humano, or a limited disciplinary superintendency of the Church], the meritoriousness of good works, indulgences, the worship of the Virgin, saints, and relics, the sacraments (other than baptism and the Eucharist), the dogma of transubstantiation and the Sacrifice of the Mass, purgatory, and prayers for the dead, auricular confession, celibacy of the clergy, the monastic system, and the use of the Latin tongue in public worship, for which the vernacular languages were substituted.
Sola fide ("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.
Priesthood of all believers
The universal priesthood of believers implies the right and duty of the Christian laity not only to read the Bible in the vernacular, but also to take part in the government and all the public affairs of the Church. It is opposed to the hierarchical system, which puts the essence and authority of the Church in an exclusive priesthood, and makes ordained priests the necessary mediators between God and the people". See also Schaff "The Principle of Protestantism, German and English" (1845).