"The choice of Solomon as one of the writers of the Bible, at first sight startles, but on deeper study instructs. We would have expected a man of more exemplary life a man of uniform holiness. It is certain that in the main, the vessels which the Spirit used were sanctified vessels. 'Holy men of old spoke as they were moved by the Holy Ghost.” But as they were all corrupt at first, so there were diversities in the operation whereby they were called and qualified for their work. There were diversities in the times, and degrees of their sanctification. Some were carried so near perfection in the body, that human eyes could no longer discern spot or wrinkle; in others the principle of grace was so largely overlaid with earthliness, that observers were left in doubt whether they had been turned to the Lord’s side at all. But the diversity in all its extent is like the other ways of God; and He knows how to make either extreme fall into its place in the concert of his praise. He who made Saul an apostle, did not disdain to use Solomon as a prophet. Very diverse were the two men, and very diverse their life course; yet in one thing they are perfectly alike. Together in glory now they know themselves to have been only sinners, and agree in ascribing all their salvation to the mercy of God.
Moreover, although good men wrote the Bible, our faith in the Bible does not rest on the goodness of the men who wrote it. The fatal facility with which men glide into the worship of men may suggest another reason why some of the channels chosen for conveying the mind of God were marred by glaring deficiencies. Among many earthen vessels, in various measures purged of their filthiness, may not the Divine Administrator in wisdom select for actual use some of the least pure, in order by that grosser argument to force into grosser minds the conviction that the excellency of the power is all of God?
If all the writers of the Bible had been perfect in holiness—if no stain of sin could be traced on their character, no error noted in their life, it is certain that the Bible would not have served all the purposes which it now serves among men. It would have been God-like indeed in matter and in mould, but it would not have reached down to the low estate of man—it would not have penetrated to the sores of a human heart. For engraving the life lessons of his word, our Father uses only diamonds: but in every diamond there is a flaw, in some a greater and in some a less; and who shall dare to dictate to the Omniscient the measure of defect that blinds Him to fling the instrument as a useless thing away?
When God would leave on my mind in youth the lesson that the pleasures of sin are barbed arrows, he uses that same Solomon as the die to indent it in. I mark the wisdom of the choice. I get and keep the lesson, but the homage of my soul goes to God who gave it, and not to Solomon, the instrument through which it came. God can make man’s wrath to praise him, and their vanity too. He can make the clouds bear some benefits to the earth, which the sun cannot bestow. He can make brine serve some purposes in nature which sweet water could not fulfil. So, practical lessons on some subjects come better through the heart and lips of the weary repentant king, than through a man who had tasted fewer pleasures, and led a more even life."
- William Arnot, Studies in Proverbs (Laws from Heaven for Life on Earth)