Here is an article from christianpioneer.com blog archive that describes a potential risk in fundamentalism if taken too far.
Bunker Christianity
There have been historical times of opposition and even persecution where Christians have responded defensively. The term “fundamentalism” comes from a series of booklets called the Fundamentals written 100 years ago in response to the rising tide of secularism seen with Darwin, Freud, and Marx enthusiastically taken up in colleges as an alternative to Christianity.
Hymns like “Onward Christian Soldiers” often resonate with a desire for a militant engagement with the world that can foster either a defensive ossification or alternatively a prideful bellicosity. However, Christians are rather called to be prepared to give a reason for the hope that is within them.
Christians under siege can react to perceived threat with fear and anger which weakens faith in their Savior and a strengthens of faith in themselves (the flesh). This usually happens when walking in truth and humility seems uncertain and being “right” seems a more concrete position. Being “right” usually means adherence to doctrines, rituals, traditions, and practices of men. Walking in truth usually means a humble surrender to the work of the Holy Spirit and unreserved trust in Jesus.
Being “right” may manifest in creeds, organizational systems, crusades, seminaries, and even inquisitions. Walking in truth often seems to engender a passivity that may lead anywhere from being ignored to being burned alive. Adversity usually exposes the limitations of being “right”. A person may cling to a particular bible translation, an achievement such as having made Jesus Lord of his life or baptism, a tradition such as generations of denominational faithfulness, or faithful adherence to a practice such as Sabbath or dietary observances, however, ultimately being “right" elevates self and walking in truth brings us closer to him who is truth.
Christians who have sought the comfort of security in a defensive position often find themselves contending with other Christians over various elements of doctrine, bible versions, prayer formats, color of choir robes, or any deviation from what has been defined as “right”. Often sermons from this vantage point carry the theme of how bad everyone else is and how good we are.
Christianity was always intended to be transcendent to the world, not promoting it, entangled with it, or in the case of “bunker" Christianity even sniping at it. There is a book hundreds of years old called, “The Practice of the Presence of God” by a Brother Lawrence. Brother Lawrence could not often be called “right”, but what he shows is a simple and complete faith in God. In a way, his various errors are useful in demonstrating by contrast how little faith depends on intellectual achievement, meticulous practice, or getting things exactly “right”.
Satan has always had success getting humans to try to take control of things. When driven into a defensive posture, we often become vulnerable to this temptation by thinking we are contending for the faith by attacking other Christians or fighting their error. Christians are called to exhort, encourage, even admonish but most of all to love other Christians. When under attack or even put to death, our God is not so weak as to need us to fight the world or each other.
