If someone would ask me, "What is a Reformed church?" this is what I am going to tell him:
A Reformed church is a branch of the one, holy, catholic, and apostolic church that confesses the ultimate authority of Scripture in matters of doctrine and conduct.
Reformed churches subscribe to the essential doctrines of Scripture summarized in the creeds of the ancient church – the Apostles' Creed, the Nicene Creed, and the Athanasian Creed.
In every Reformed congregation, these basic doctrines contained in the creeds are carefully explained in the Reformed confessions of the 16th and 17th centuries.
These confessions are subordinate standards in the church and are recognized as faithful summaries of these Christian doctrines.
Such confessions include the French Confession of 1559, the Scots Confession of 1560, the Belgic Confession of 1561, the Heidelberg Catechism of 1563, the Second Helvetic Confession of 1566, the Thirty-Nine Articles of 1571, the Canons of Dort (1618-1619), the Westminster Standards (1646-1647), and other Reformed standards.
The first Reformed churches were established around 1519 in the Swiss region and in some parts of Germany and France.
The spread of the Reformed faith has reached the Netherlands, the British isles, including Scotland, some parts of continental Europe, towards the latter part of 16th century.
In the succeeding centuries the Reformed faith has spread in the Americas and the continents of Africa and Asia, including the Carribean and the islands in the Pacific.
Thus one could find a Reformed church in every continent of the world. It is not the predominant Christian church in the world but interest in its teachings and practice has grown worldwide in the last 25 years or so.
Aside from the supremacy of Scripture over other authorities in matters of faith and and conduct in life, Reformed churches also believe in the sovereignty of the triune God in creation, providence and redemption, the two natures of Christ, and the fallenness and depravity of man.
Other distinct doctrines of Reformed churches include covenant theology, the precedence of regeneration over faith and repentance, the salvation of sinners by grace alone, and justification through faith alone in Christ alone.
The Reformed church also believes in the definite atonement or particular redemption of Christ, the irresistible grace of the Spirit of God, and the final perseverance of the saints by the gracious preservation of God.
A Reformed church has presbyterial (elder-ruled) church government. It practices plurality (more than one) and parity (equality in power and authority) of elders. Elders, which include the ministers, are the undershepherds of Christ, who is the Chief Shepherd and Lord of the Church.
Part of its distinct beliefs also include the word of God regulating the public worship of God, the sacraments of baptism and holy communion as signs and seals of God's covenant, the reign of Christ in the here and now and His glorious appearance at the last day.
These are some of the essential teachings found in Reformed churches. An outsider or someone who is new to Reformed theology must be aware of the diversity of conclusions and applications of these beliefs within Reformed orthodoxy.
As a new comer to this tradition, I am aware that my knowledge of the Reformed faith still needs to grow. One thing I know for sure though. The Reformed faith always seeks to conform its teachings and practice to the inspired and authoritative written word of God.
A church that claims to be Reformed but neglects the Bible, is ignorant of or thrashes its biblical traditions, and do not seek to be normed and reformed by the holy Word of God, that is, the Bible, is not a faithful one.