The Four Marks of the Church, also known as the Attributes of the Church, describes four distinctive adjectives of traditional Christian ecclesiology as expressed in the Niceno-Constantinopolitan Creed completed at the First Council of Constantinople in AD 381: "[We believe] in one, holy, catholic, and apostolic Church."
This ecumenical creed is today recited in the liturgies of the Catholic Church (both Latin and Eastern Rites), the Eastern Orthodox Church, the Oriental Orthodox Churches, the Assyrian Church of the East, the Moravian Church, the Lutheran Churches, the Methodist Churches, the Presbyterian Churches, the Anglican Communion, and by members of the Reformed Churches, although they interpret it in very different ways, and some Protestants alter the word "Catholic" in the creed, replacing it with the word "Christian".
While many doctrines, based on both tradition and different interpretations of the Bible, distinguish one denomination from another (largely explaining why there are many different ones), the Four Marks represent a summary of what many clergy and theologians have historically considered to be the most important affirmations of Christianity.
The ideas behind the Four Marks have been in the Christian Church since early Christianity. Allusions to them can be found in the writings of 2nd-century early Church Father and bishop Ignatius of Antioch. They were not established in doctrine until the First Council of Constantinople in 381 as an antidote to certain heresies that had crept into the Church in its early history. There the Council elaborated on the Nicene Creed, established by the First Council of Nicaea 56 years before by adding to the end a section that included the affirmation: "[We believe] in one, holy, catholic, and apostolic Church." The phrase has remained in versions of the Nicene Creed to this day.
In some languages, for example, German, the Latin "catholica" was substituted by "Christian" before the Reformation by some, although this was an anomaly and continues in use by some Protestant churches today.