This Latin phrase is derived from the Second Epistle to the Corinthians in the New Testament, chapter 3, verse 6. The phrase is translated into English as follows: “Who also hath made us able ministers of the new testament; not of the letter, but of the spirit: for the letter killeth, but the spirit giveth life.”
This verse highlights the difference between the old and new covenants, indicating that the new covenant is one of the spirit rather than strictly bound by the law (the letter). It emphasizes the importance of comprehending the spiritual essence behind the law instead of being restricted to its literal interpretation.