The quote emphasizes that Christianity cannot be a secondary aspect of one’s life; it must be the primary focus. When Christianity is merely incidental, it lacks the transformative power that comes from being deeply rooted in faith. Vanauken suggests that this lack of a dominant belief can lead to a life filled with competing priorities, resulting in a sense of imbalance. This imbalance often causes friction between Christians and those who do not share their faith, as Christians are driven by a profound purpose while others may struggle with their priorities. The quote highlights the importance of commitment in any belief system and how it shapes one's actions and perceptions of life. Ultimately, a life without an overarching commitment can lead to confusion and dissatisfaction. True freedom and growth come from embracing a central belief that guides decisions and provides meaning.