The LCMS affirms the verbal, plenary inerrancy of the Bible. This means that the very words of Scripture (as originally written) are infallibly true and completely free from error in all matters—whether doctrine, history, science, or ethics. The Bible is inerrant not merely in matters of faith and practice but in its entirety.

The inerrancy of Scripture is grounded in the inspiration of the Holy Spirit. God not only inspired the thoughts and concepts but superintended the selection and arrangement of words, so that the resulting text is exactly what God intended. Inerrancy applies to the original manuscripts (autographa); manuscript variants and translation differences are acknowledged, but the LCMS affirms that the original inspired texts were inerrant.

The LCMS employs the historical-grammatical method of interpretation, which seeks to understand the text in its historical context, according to the rules of grammar and syntax, and according to the author's intended meaning. This method acknowledges different genres (narrative, poetry, prophecy, wisdom literature) and interprets each according to its kind. However, the commitment to inerrancy means that all Scripture, rightly understood, is truthful and authoritative. The LCMS rejects the view that Scripture can be errant in some areas while authoritative in others.