“Every word of God is pure: he is a shield unto them that put their trust in him” (Proverbs 30:5).
“Do we then make void the law through faith? God forbid: yea, we establish the law” (Romans 3:31).
When Paul made this statement in Romans, he was making it clear that faith in God’s grace did not make the law null and void, nor did it declare the law unworthy. It was the exact opposite. The law declared us unworthy and exposed our need of grace. By accepting God’s grace, we establish the fact that the law is pure in every way and that we are sinners in desperate need of a Savior.
Revelation illustrates it another way:
Revelation 10:9-10
(9) And I went unto the angel, and said unto him, Give me the little book. And he said unto me, Take it, and eat it up; and it shall make thy belly bitter, but it shall be in thy mouth sweet as honey.
(10) And I took the little book out of the angel’s hand, and ate it up; and it was in my mouth sweet as honey: and as soon as I had eaten it, my belly was bitter.
Why would God’s Word taste so sweet and at the same time be so bitter? Because God’s Word is wonderful. It’s just not always easy to take. That’s not an indictment of God’s Word. It’s an indictment of our own sinful nature. Every word of God is pure, even the words that condemn us because they establish the goodness and purity of God.