The central message of this sermon is that the Bible is a reliable historical document due to its unique characteristics, particularly in terms of manuscript quantity and quality. The speaker argues that when using a valid standard, such as the one employed by historians, the Bible passes with flying colors, making it one of the most reliable ancient documents. This advances the belief that the Bible's reliability can be established through empirical evidence, rather than solely relying on faith or tradition. Ultimately, the takeaway is that the Bible's claims to being a factual and valid account of historical events should not be dismissed due to perceived flaws in its transmission or language use, but rather be taken seriously as a historically accurate document.