The Protestant Reformation was a 16th- and 17th-century movement intent on reshaping and revitalizing the Christian church.
Martin Luther's formulation of the nature of salvation as justification by faith alone is the most significant theological legacy of the Protestant Reformation, Pitts writes.
The church had experienced many reform movements in the past, but this one was unique: It produced challenging interpretations of Christianity and rapidly won a large following.
The old wine skins could not hold the new, and the church divided. Christianity would now be divided into three major families, adding Protestantism to Roman Catholicism and Orthodoxy.
This era of reform is usually dated from Luther's public protest in1517 to the end of the Religious Wars in 1648, or to 1689 when the English Parliament passed the Act of Toleration granting most Christian denominations the right to worship.
The reform focused initially on internal church matters but also influenced the political and social life of Europe – and the new world of the Americas as well.
The question of why reform occurred at this time has generated much discussion.
The vitality of the church in the era just preceding reform has been closely examined by historians. They find evidence of a great deal of devotion to faith.
But there is also evidence of anticlericalism, resentment toward the clergy who took advantage of their privileged position in society.
Erasmus' dictum ad fontes (back to the sources) summarized a key goal of Renaissance scholars.
They recovered old manuscripts and learned ancient languages. Similarly, the early Protestant reformers learned to read Scripture in the original Hebrew and Greek, opening for them multiple new understandings of the faith.
Technology played a role as well. Whereas earlier reform movements did not have printing presses, the Reformation took full advantage of the new printing press to disseminate its ideas.
Historians have examined the role of city and rural areas, of class and economic differences, and the role of the family and political decision-makers in explaining the success of the Reformation.
Martin Luther is credited with the origin of Protestantism. Deeply concerned for his soul's salvation, he abandoned law school for the monastery.
In his personal quest for assurance of salvation, he found that struggling to please God by moral striving did not remove his despair. Neither did careful observance of penance for his sins.
Diligently working through the Scripture, Luther read Romans 1:16-17 in a new way. He came to the conclusion that the righteousness that God requires is also what God grants.
Luther now proposed that salvation is based on justification by faith in God rather than on human endeavor. He affirmed that salvation is by God's grace – the gift of forgiveness.
The church had always taught that salvation was God's gift, but in practice many people thought in terms of moral effort that earned salvation.
Luther argued for a responsible life lived for others not in order to be saved, but because we have been saved. The Christian ethic was grounded in gratitude to God.
Luther's formulation of the nature of salvation as justification by faith alone is the most significant theological legacy of the Protestant Reformation. Virtually all modern denominations have been influenced by Luther's views.
The Reformation became public when Luther protested the church's sale of indulgences by posting in Latin "95 Theses" or statements for debate on the door of the Castle Church in Wittenburg on Oct. 31, 1517.
He argued that whereas in the Latin translation "penance" had come to mean an occasional act, the Greek original meant a life lived in a daily attitude of humility.
Moreover, he criticized the church for taking money from Christians who believed their time in Purgatory would be shortened by purchasing indulgences.
The theses were translated into German, printed and widely disseminated. The Reformation was moving from an individual's interpretation to becoming a movement.
Church authorities challenged Luther in public debate at Leipzig where Luther denied that pope and councils were the final authorities for the church.
Instead, he emphasized the authority of Scripture alone. Virtually all Protestants following Luther have looked to Scripture for their authority.
Luther also developed the idea of the priesthood of all believers, providing theological support for lay people constituting the church.
Protestants stressed their two major principles by the formulas sola fide/sola gratia (by faith alone/by grace alone) and sola scriptura (Scripture alone).
These ideas were at the core of the new Protestant Reformation thought and still today have a powerful influence on Western culture. These two ideas affected much in the practice of the church.
In the medieval church, the paths of salvation centered on the seven sacraments. Protestants reduced these to two, arguing that Christ commanded only baptism and the Lord's Supper. More important, they stressed the Word of God as the locus of salvation.
Catholics and Protestants both worshipped in word and sacrament. But for Protestants preaching the Word in the vernacular became more important than observance of the Lord's Supper. In worship, focus shifted from altar to pulpit.
Churches accepting Protestantism were undergoing a major transformation in their weekly gatherings for worship. Many other beliefs also changed.
For example, Protestants did not find evidence in Scripture for devotion to saints or for Purgatory.
Bill Pitts is professor of church history at Baylor University in Waco, Texas, and is currently serving as president of the Baptist History and Heritage Society.
Editor's note: This is the first of two articles by Pitts on the Protestant Reformation. Part two will appear tomorrow.