Protestantism, or Protestant Christianity, gained its name from the protestation — that is, the document of protest issued in 1529 by six German princes and representatives of fourteen south German cities. This alliance was rebelling against the religious decisions of the imperial diet of Speyer, which had tried to unify the territories of the Holy Roman Empire — that is, the lands of modern Switzerland, Austria, and Germany — by requiring uniformity of worship.

The document declares two principles that are the heart of the Protestant understanding of Christianity. The same pair of principles had been declared by the German priest Martin Luther at his famous confrontation with both the Roman Catholic Church and the Holy Roman emperor in 1521.

The first principle is that the word of God is a greater authority than any human authority.

The second principle is that conscience alone justifies opposition to certain ecclesiastical decrees. . . .

Protestantism began as a modest movement to address certain grievances within the existing structure of church and state. Even after Luther appealed to conscience over church authority, he cautioned some of his more radical followers that just any theological view could not be permitted. The protesters at Speyer argued for freedom of religious conscience, but only as a way to defend their own understanding of Christianity.

BROOKS HOLIFIELD (Professor of Church History, Emory University): Two themes stand at the center of the Protestant tradition. One is the reliance on the authority of Scripture. This ancient body of writings illumines the way we see the world. The second theme at the heart and center of the Protestant movement has been this conviction that we are forgiven even though we are unforgivable, that we do not earn our salvation, it is given to us freely as a gift. We are enabled to be what we are.

In the 20th century, the ecumenical movement has renewed the Christian assessment of other religions. The old attitude of rejecting and condemning non-Christian religions has been challenged. The traditional evangelical message of simplicity and clarity, focusing on the reliability of the Bible and salvation in Jesus Christ, has attracted a great following in the latter half of the 20th century.

Just as religiously conservative Protestants have supported politically conservative causes, so religiously liberal Protestants have actively supported politically liberal causes. Issues like homosexuality, abortion, foreign policy, and environmentalism have become religious hot buttons. They invoke powerful religious ideals and commitments as Christians struggle with issues that inflame modern political life. Protestant is a broad and flexible term.

If asked by a survey, few who belong to Protestant churches would identify themselves first as a Protestant. A more likely first description would be Christian or the name of a particular denomination or a defining adjective such as Evangelical or Pentecostal.

Various Protestants have differing views of the nature of the church, of ministry, of worship, and of religious authority. They celebrate baptism and the Lord’s Supper in different ways, and they attach different meanings to these two sacraments, and despite the diversity of Protestant ideas with the volatility that this brings, Protestantism’s fundamental commitments continue to give meaning and vitality to this large and worldwide expression of the Christian religion.