Verse 20 offers some insight.......
For there is not a just man upon earth, that doeth good, and sinneth not.
Here's some info to consider
Ecclesiastes 7:15-18
If one misjudges in the manner of the paradox described here and therefore reacts wrongly, the effect could lead to one of two possible spiritual extremes. Thus, Solomon gives his cautions.
Perhaps these possible alternatives can be illustrated this way: Imagine a horizontal line drawn across a blank sheet of paper. Both the beginning of the line on the left and the end of the line on the right represent extreme reactions as well as the results produced should a person make wrong choices within the trial.
One can react radically to the left, becoming completely liberal, by choosing simply to give up. The result would be spiritual death. The other extreme reaction would be to choose to turn sharply right, becoming righteous over much, and the bad fruit also produces spiritual death.
Why? Because either extreme is rebellion against God's grace. In Psalm 73, Asaph neither gave up nor attempted to become super-righteous so that
God would be impressed and owe him the blessing of relieving the pressures of his suffering. He chose a path right down the middle, to trust God.
Turning to the right to become over-righteous is the choice we should be more concerned about. Why? Because most of the truly converted will not simply give up. They may become weary and confused, but they will not walk away from God's mercy.
John W. Ritenbaugh
Ecclesiastes and Christian Living (Part Twelve): Paradox, Conclusion
John Gill's Commentary says
Ecclesiastes 7:16
Be not righteous over much
This is not meant of true and real righteousness, even moral righteousness, a man cannot be too holy or too righteous; but of a show and ostentation of righteousness, and of such who would be thought to be more righteous and holy than others, and therefore despise those who, as they imagine, do not come up to them; and are very rigid and censorious in their judgment of others, and very severe in their reproofs of them; and, that they may appear very righteous persons, will do more than what the law requires of them to do, even works of supererogation, as the Pharisees formerly, and Papists now, pretend, and abstain from the lawful use of things which God has given to be enjoyed; and macerate their bodies by abstinence, fastings, pilgrimages, penance, scourges, and the like, as the Eremites among the Christians, and the Turks, as Aben Ezra on the place observes; and many there be, who, by an imprudent zeal for what they judge right, and which sometimes are mere trifles, and by unseasonable reproofs for what is wrong, expose themselves to resentment and danger. Some understand this of political and punitive justice, exercising it in too strict and rigorous a manner, according to the maxim, "summum jus saepe summa injuria est"
F23; and Schultens
F24, from the use of the word in the Arabic language, renders it, "be not too rigid"; and others, in a contrary sense, of too much mercy and pity to offenders. So the Midrash; and Jarchi illustrates it by the case of Saul, who had mercy on the wicked, and spared Agag. The Targum is,
``be not over righteous at a time that a sinner is found guilty of slaughter in thy court of judicature, that thou shouldest spare and not kill him;''
neither make thyself over wise;
above what is written, or pretend to be wiser than others. So the Arabic version, "show not too much wisdom"; do not affect, as not to be more righteous than others, so not more wise, by finding fault with present times, or with the dispensations of Providence, or with the manners and conduct of men; setting up for a critic and a censurer of men and things; or do not pry into things, and seek after a knowledge of them, which are out of your reach, and beyond your capacity;
why shouldest thou destroy thyself?
either by living too strictly and abstemiously, or by studying too closely, or by behaving in such a manner to men, as that they will seek thy destruction, and bring it on thee: or "why shouldest thou", or "whereby", or "lest, thou shouldest be stupid"
F25; lose thy sense and reason, as persons who study the knowledge of things they have not a capacity for: or why shouldest thou become foolish in the eyes of all men by thy conduct and behaviour? or, "why shouldest thou be desolate"
F26; alone, and nobody care to have any conversation and acquaintance with thee?
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