3 Principles of Mere Christianity

In the realm of Christian theology, C.S. Lewis’s “Mere Christianity” stands as a seminal work, offering a unique perspective on the fundamentals of the faith. This book, a compilation of Lewis’s radio talks during World War II, presents a compelling argument for a unified Christian belief system, focusing on what he terms the “mere” or essential elements shared by all denominations. Here, we delve into three key principles that form the backbone of Lewis’s argument.

The Principle of Natural Law

One of the cornerstone concepts in Lewis’s philosophy is the idea of Natural Law. This principle suggests that there exists an inherent moral code, a set of universal standards, that govern human behavior and relationships. Lewis argues that this law is not something imposed from without, but rather something that is innate within us, a sort of internal compass that guides our actions and judgments.

“If there is a power behind the universe that cares about me and loves me, then it follows that I owe something back,” Lewis writes. This concept of a reciprocal relationship, of duty and obligation, forms the basis of his understanding of Natural Law.

To illustrate this, Lewis often turns to everyday examples. For instance, he might say, “We know it is wrong to cheat in exams, not because some authority has said so, but because our conscience tells us so. This is the voice of Natural Law speaking within us.”

The Principle of Triune Existence

Another central tenet of Lewis’s philosophy is the idea of Triune Existence, or the concept of the Trinity. Lewis argues that the Christian understanding of God as a Trinity—Father, Son, and Holy Spirit—is not just a theological concept, but a reflection of the very nature of existence itself.

“When we think of the Trinity, we are not dealing with the inscrutable intricacies of abstract thought,” Lewis explains. “We are dealing with something as tangible and inevitable as the discovery that the three dimensions of space cannot be eliminated from the universe.”

In other words, just as we cannot eliminate the dimensions of space from our physical reality, so too cannot we eliminate the concept of triunity from our spiritual reality. This principle, Lewis argues, is a key to understanding the nature of God and our relationship with Him.

The Principle of Self-Sacrifice

The final principle we will explore is that of self-sacrifice. Lewis argues that the ultimate demonstration of love and the highest moral good is self-sacrifice. This concept is central to the Christian narrative, particularly in the story of Jesus’ crucifixion.

“Self-sacrifice is the heart of Christianity,” Lewis asserts. “It is not a matter of doing extraordinary things. It is a matter of ordinary people, under ordinary circumstances, doing what they ought to do, and doing it as well as they can.”

For Lewis, self-sacrifice is not just about grand gestures, but about the daily choices we make to put others first, to live a life of service and love. It is about aligning our will with the will of God, and in doing so, finding our true purpose and fulfillment.

These three principles—Natural Law, Triune Existence, and Self-Sacrifice—form the foundation of Lewis’s “Mere Christianity.” They offer a compelling framework for understanding the core beliefs of the Christian faith, and provide a starting point for further exploration and dialogue.