I am preaching on Psalm 12 this week. Here is a quote from John Calvin on why we need to be reminded that God’s Words are true and that he “promises nothing in vain.” He is commenting on Psalm 12:7, “The words of the Lord are pure words, like silver tried in a furnace of earth, purified seven times.”
There is no man, it is true, who will not frankly confess that he entertains the same conviction which David records here, that the words of Jehovah are pure; but those who while lying in the shade and living at their ease liberally extol by their praises the truth of God’s word, when they come to struggle with adversity in good earnest, although they may not venture openly to pour forth blasphemies against God, often charge him with not keeping his word. Whenever he delays his assistance, we call in question his fidelity to his promises and murmur just as if he had deceived us. There is no truth that is more generally received among men than that God is true; but there are few who frankly give him credit for this when they are in adversity. It is, therefore, highly necessary for us to cut off the occasion of our distrust; and whenever any doubt respecting the faithfulness of God’s promises steals in upon us, we ought immediately to lift up against it this shield, that the words of the Lord are pure.