In Protestant theology

Theology

Theology is the systematic and rational study of religion and its influences and of the nature of religious truths, or the learned profession acquired by completing specialized training in religious studies, usually at a university or school of divinity or seminary.-Definition:Augustine of Hippo...

, the Marks of the Church are those things by which the true church may be recognized. Three marks are usually enumerated: the preaching of the Word the administration of the sacraments and church discipline

Church discipline

Church discipline comes in two types: formative and corrective. Formative discipline, or discipleship, seeks to help form the character and life of the believer. In this sense, every church disciplines it members. Jonathan Leeman has noted that "every church disciplines its members formally...

. The Belgic Confession

Belgic Confession

The Confession of Faith, popularly known as the Belgic Confession, is a doctrinal standard document to which many of the Reformed churches subscribe. The Confession forms part of the Reformed Three Forms of Unity...

 devotes a chapter (Article 29) to the "Marks of the True Church" and lists them as follows:
Louis Berkhof

Louis Berkhof

Louis Berkhof was a Reformed systematic theologian whose written works have been influential in seminaries and Bible colleges in the United States and Canada and with individual Christians in general throughout the 20th century.-Personal life:...

 notes that Reformed theologians have differed as to the number of marks - Theodore Beza

Theodore Beza

Theodore Beza was a French Protestant Christian theologian and scholar who played an important role in the Reformation...

 spoke of only one (preaching), John Calvin

John Calvin

John Calvin was an influential French theologian and pastor during the Protestant Reformation. He was a principal figure in the development of the system of Christian theology later called Calvinism. Originally trained as a humanist lawyer, he broke from the Roman Catholic Church around 1530...

 and Heinrich Bullinger

Heinrich Bullinger

Heinrich Bullinger was a Swiss reformer, the successor of Huldrych Zwingli as head of the Zurich church and pastor at Grossmünster...

 spoke of two (preaching and sacraments) while Peter Martyr and Zacharias Ursinus

Zacharias Ursinus

Zacharias Ursinus was a sixteenth century German Reformed theologian, born Zacharias Baer in Breslau . He became the leading theologian of the Reformed Protestant movement of the Palatinate, serving both at the University of Heidelberg and the College of Wisdom...

 spoke of three - preaching, sacraments and discipline. Nevertheless, Edmund Clowney

Edmund Clowney

Edmund Prosper Clowney was a theologian, educator, and pastor. Born in Philadelphia, Pennsylvania, he earned a Bachelor of Arts from Wheaton College in 1939, a Bachelor of Theology from Westminster Theological Seminary in 1942, a Master of Sacred Theology from Yale Divinity School in 1944, and a...

 points out that Calvin "included discipline in the proper observance of the sacraments."
R. Albert Mohler, Jr.

R. Albert Mohler, Jr.

Mohler's approach to Muslims is driven by his belief in the relevance of the Christian Gospel to all people.-Media appearances:Mohler appeared on MSNBC's Donahue on August 20, 2002. The subject was Christian evangelization of Jews...

 calls church discipline the "missing mark" of the church.

See also

• On the Councils and the Church
  On the Councils and the Church
  On the Councils and the Church is a treatise by Protestant ReformerMartin Luther on ecclesiology, on a later stage of his life.On the Councils and the Church is known best for its teaching, dealt in the third part of the book, of the "seven marks of the Church", of which the One Holy Catholic and...
  
  
• Means of grace
  Means of Grace
  The Means of Grace in Christian theology are those things through which God gives grace. Just what this grace entails is interpreted in various ways: generally speaking, some see it as God blessing humankind so as to sustain and empower the Christian life; others see it as forgiveness, life, and...
  
  
• Chicago-Lambeth Quadrilateral
  Chicago-Lambeth Quadrilateral
  The Chicago-Lambeth Quadrilateral, frequently referred to as the Lambeth Quadrilateral or the Lambeth-Chicago Quadrilateral, is a four-point articulation of Anglican identity, often cited as encapsulating the fundamentals of the Communion's doctrine and as a reference-point for ecumenical...