The quote highlights how both religious and secular ideologies can lead individuals to justify their actions, often with a sense of moral superiority. It suggests that people frequently use their beliefs, whether divine or scientific, to validate their choices and even to engage in conflict. This mindset creates a dangerous certainty, where individuals feel justified in their actions without questioning their motives or the consequences. Prothero draws attention to the potential for both religious zealots and secular advocates to believe they are on the 'right side' of an issue, leading to harm in the name of their convictions. The underlying message calls for a critical examination of our beliefs and a recognition of the complexities of human motivations. It emphasizes the importance of humility in our convictions, reminding us that certainty can often blind us to the truth. Ultimately, the quote serves as a caution against the dangers of absolute certainty in any ideology.