What Is the Church?

What Is the Church? offers a concise introduction to the doctrine of the church, exploring what Scripture and the historic Christian faith teach about the nature, marks, and calling of the people of God.

Dr. R.C. Sproul organizes this booklet around the four attributes of the church confessed in the Nicene Creed—one, holy, catholic, and apostolic—and examines each in turn. He addresses the challenges that denominationalism, the ecumenical movement, and theological pluralism pose to the church’s unity, arguing that genuine oneness must be grounded in a shared confession of the apostolic gospel rather than in organizational structure alone. Sproul also distinguishes between heresy and error, explaining how the church has historically identified and responded to teachings that threaten its foundational commitments.

The booklet explores the visible and invisible church, the meaning of holiness as rooted in the biblical concept of ekklesia—a people called out by God—and the universality of the church across time and place. Sproul discusses apostolic authority, the role of servant leadership, and the Reformation’s three marks of a true church: the faithful preaching of the gospel, the proper administration of the sacraments, and the exercise of church discipline. He concludes with pastoral guidance on the serious question of when a Christian may or must leave a church body.

Key Themes

• The four Nicene attributes of the church: one, holy, catholic, and apostolic
• The tension between institutional unity and confessional integrity
• The distinction between the visible and invisible church
• The Reformation’s marks of a true church and their contemporary application

Featured Quotes

“There is always a price tag for that, and historically, the price tag has been the confessional purity of the churches.”

“If we look at the root meaning of the term ekklesia in the Scriptures, we see that etymologically, it means something that is called out of something else.”