Karl Barth was a Swiss Reformed theologian widely regarded as one of the most influential Protestant thinkers of the 20th century. His work was a seen as a rejection to the liberal Protestantism of the 19th century (which blended faith with modern culture, philosophy, and human experience) and a return to the centrality of divine revelation in Jesus Christ.
Opposition to World War 1 and 2
During World War 1, Barth was horrified when many of his liberal professors signed a manifesto supporting Germany's war efforts, exposing what he saw as theology's dangerous captivity to culture and nationalism. In response, he wrote his explosive Commentary on the Epistle to the Romans (1919) where he insisted that true knowledge of God comes only through God's self-revelation, not human reason or experience. This rebuked attempts to subordinate theology to culture and politics.
He further expounded his thoughts in his book Church Dogmatics (1932).
Just before World War 2, he became the primary author of the Barmen Declaration (1934), a foundational confession for the anti-Nazi Confessing Church. It rejected any “German Christian” movement that subordinated the gospel to Hitler, the state, or race, declaring: “Jesus Christ, as he is attested for us in Holy Scripture, is the one Word of God.” This document reminded the church that its first loyalty is always to Christ, not to any earthly power, ideology, or “spirit of the age.”
Differences with Reformation
Although Barth was off the Reform tradition, he was definitely not a classical Protestant. (He is often called a neo-orthodox thinker.)
For instance, he did not accept the inerrancy of Scripture. The Reformers (Luther and Calvin) viewed the Bible itself as the inspired, authoritative Word of God—generally inerrant in its original sense.
Barth distinguished sharply: Jesus Christ is the one true Word of God; the Bible is a human witness that becomes the Word of God when God sovereignly speaks through it. This makes Scripture dynamic and event-based rather than statically infallible.
In another instance, Barth was absolutist about nature. He rejected any “point of contact” in fallen human nature or creation for knowing God—insisting on revelation alone can lead us to the knowledge of God. This is in contrast to the Reformers who felt that natural theology can lead us to some (albeit distorted) knowledge of God.
Legacy
Today, Barth is remembered for centering Christianity. Barth revitalized 20th-century theology by making it more biblically serious and Christ-centered at a time when liberalism had diluted the faith.
