The Orthodox Presbyterian Church (OPC) is a confessional Presbyterian denomination located primarily in the northern United States. It was founded by conservative members of the Presbyterian Church in the United States of America(PCUSA) who strongly objected to the Modernist theology during the 1930s. It has had an influence on evangelicalism far beyond its size.

History
The Orthodox Presbyterian Church was founded in 1936, largely through the efforts of John Gresham Machen. Machen and others had founded Westminster Theological Seminary in 1929, in response to a re-organization of Princeton Theological Seminary. In 1933, Machen, concerned about Liberal Christianity|liberal theology tolerated by Presbyterians on the mission field, formed the Independent Board for Presbyterian Foreign Missions. The next Presbyterian General Assembly reaffirmed that Independent Board was unconstitutional and gave the associated clergy an ultimatum to break their links. When Machen and seven other clergy refused, they were suspended from the Presbyterian ministry.

On June 11, 1936, Machen and a group of conservative ministers, elders, and laymen met in Philadelphia to form the Presbyterian Church of America (not to be confused with the Presbyterian Church in America, or PCA, which came about decades later). Machen was elected as the first moderator. The PCUSA filed suit against the fledgling denomination for its choice of name, and in 1939, the denomination adopted its current name, the Orthodox Presbyterian Church.

Machen died in January 1937. Later that year, a significant faction of the OPC, led by Carl McIntire, broke away to form the Bible Presbyterian Church, a denomination which, unlike the OPC, required abstinence from alcohol and taught premillennialism.

Congregations
As of 2014, The OPC had 281 congregations. In 2019, Escondido Orthodox Presbyterian Church received media attention as the church of which John Earnest, alleged perpetrator of the 2019 Poway synagogue shooting|Poway synagogue shooting, was a member.  Its pastor, Zake Keele, condemned the shooting as an "act of evil."

Doctrine
The OPC system of doctrine is the Reformed faith, also called Calvinism. Calvin's doctrines continued to develop after his death, and a particular evolution of them was set forth by a 17th-century assembly of British theologians in the Westminster Standards (which include the Westminster Confession of Faith and the Westminster Larger Catechism|Larger and Westminster Shorter Catechism|Shorter Catechisms). The OPC holds to the Westminster Standards with the American revisions of 1788.

The OPC provides the following summary of its doctrine:

 The Bible, having been inspired by God, is entirely trustworthy and without error. Therefore, we are to believe and obey its teachings. The Bible is the only source of special revelation for the church today.
 The one true God is personal, yet beyond our comprehension. He is an invisible spirit, completely self-sufficient and unbounded by space or time, perfectly holy and just, and loving and merciful. In the unity of the Godhead there are three "persons": the Father, the Son, and the Holy Spirit.
 God created the heavens and the earth, and all they contain. He upholds and governs them in accordance with his eternal will. God is sovereign—in complete control—yet this does not diminish human responsibility.
 Because of the sin of the first man, Adam, all mankind is corrupt by nature, dead in sin, and subject to the wrath of God. But God determined, by a covenant of grace, that sinners may receive forgiveness and eternal life through faith in Jesus Christ. Faith in Christ has always been the only way of salvation, in both Old Testament and New Testament times.
 The Son of God took upon himself a human nature in the womb of the virgin Mary, so that in her son Jesus the divine and human natures were united in one person. Jesus Christ lived a sinless life and died on a cross, bearing the sins of, and receiving God's wrath for, all those who trust in him for salvation (his chosen ones). He rose from the dead and ascended into heaven, where he sits as Lord and rules over his kingdom (the church). He will return to judge the living and the dead, bringing his people (with glorious, resurrected bodies) into eternal life, and consigning the wicked to eternal punishment.
 Those whom God has predestined unto life are effectually drawn to Christ by the inner working of the Spirit as they hear the gospel. When they believe in Christ, God declares them righteous (justifies them), pardoning their sins and accepting them as righteous, not because of any righteousness of their own, but by imputing Christ's merits to them. They are adopted as the children of God and indwelt by the Holy Spirit, who sanctifies them, enabling them increasingly to stop sinning and act righteously. They repent of their sins (both at their conversion and thereafter), produce good works as the fruit of their faith, and persevere to the end in communion with Christ, with assurance of their salvation.
 Believers strive to keep God's moral law, which is summarized in the Ten Commandments, not to earn salvation, but because they love their Savior and want to obey him. God is the Lord of the conscience, so that men are not required to believe or do anything contrary to, or in addition to, the Word of God in matters of faith or worship.
 Christ has established his church, and particular churches, to gather and perfect his people, by means of the ministry of the Word, the sacraments of baptism (which is to be administered to the children of believers, as well as believers) and the Lord's Supper (in which the body and blood of Christ are spiritually present to the faith of believers), and the disciplining of members found delinquent in doctrine or life. Christians assemble on the Lord's Day to worship God by praying, hearing the Word of God read and preached, singing psalms and hymns, and receiving the sacraments.

OPC pastors and presbyteries teach a range of doctrines based on the historical view of the biblical creation accounts, from framework and analogical interpretations to young earth.

American politics
The 39th General Assembly, meeting in 1972, adopted a statement on abortion that included the affirmation that "voluntary abortion, except possibly to save the physical life of the mother, is in violation of the Sixth Commandment (Exodus 20:13)."

In 1993, the denomination petitioned then President Bill Clinton to continue to disallow homosexuals to serve in the military. According to the petition, "homosexuality is a reproach to any nation. It undermines the family, and poses a substantial threat to the general health, safety and welfare of our citizens." The petition claims that AIDS and "other diseases" are spread particularly through homosexual conduct.

The 68th General Assembly declared that women serving in combat positions in the military is contrary to the Bible.

In 2006-2007, a study committee formed by the General Assembly created a report that concluded that "the church should never turn its back on fellow brothers and sisters in Christ, whether they are legally or illegally in the country. We should be willing to see to the spiritual and physical needs of anyone who comes to the church." The report also recommended that illegal immigrants seek to "repent" of their legal status.

OPC ministers have held a variety of political views. Carl Trueman, an ordained minister in the OPC, has authored Republocrat: Confessions of a Liberal Conservative (pub. 2010).  Several founders of American Christian Reconstructionism (such as Rousas John Rushdoony and Greg Bahnsen) were Orthodox Presbyterian ministers.

References

Further reading
 Gatiss, Lee.  Christianity and the Tolerance of Liberalism: J.Gresham Machen and the Presbyterian Controversy of 1922-1937. London: Latimer Trust, 2008 
 Churchill, Robert King. Lest We Forget : a Personal Reflection on the Formation of The Orthodox Presbyterian Church. Philadelphia : The Committee for the Historian of The Orthodox Presbyterian Church, 1987. 
 Longfield, Bradley J. The Presbyterian Controversy: Fundamentalists, Modernists, and Moderates. New York: Oxford University Press, 1991. 
 Hart, D.G. Defending the Faith: J. Gresham Machen and the Crisis of Conservative Protestantism in Modern America. Baltimore: The Johns Hopkins University Press, 1994. 
 Hart, D.G., and John Muether. Fighting the Good Fight of Faith: A Brief History of the Orthodox Presbyterian Church. Philadelphia: The Committee on Christian  Education and the Committee for the Historian of the Orthodox Presbyterian Church, 1995. 
 North, Gary. Crossed Fingers: How the Liberals Captured the Presbyterian Church. Tyler, TX: Institute for Christian Economics. 1996. 
 Calhoun, David B., Princeton Seminary: The Majestic Testimony, 1869-1929. Carlisle, PA: Banner of Truth, 1996.
 Rian, Edwin H. The Presbyterian Conflict. Grand Rapids: Eerdmans. 1940. 
 Loetscher, Lefferts A., The Broadening Church: A Study of Theological Issues in the Presbyterian Church Since 1869. Philadelphia: University of Pennsylvania Press
 Elliot, Paul M., Christianity and Neo-Liberalism: The Spiritual Crisis in the Orthodox Presbyterian Church and Beyond, 2005, Trinity Foundation,

Other websites
The Orthodox Presbyterian Church: official website
Great Commission Publications

Orthodox Presbyterian Church