Ecclesiastes 7:15-8:1

summary
In this section The Teacher reflects on the seeming injustices and paradoxes of life, starting with righteous people sometimes perishing while wicked people prosper. He warns against extremes of self-righteousness or wickedness, urging a balanced life. True wisdom recognizes human limitations and the mystery of God’s purposes. His search for wisdom leads him to conclude that no one is entirely righteous or free from sin.

key verses
7:25, 29 I turned my mind to understand,
to investigate and to search out wisdom and the scheme of things
and to understand the stupidity of wickedness
and the madness of folly.

This only have I found:
God created mankind upright,
but they have gone in search of many schemes.

related verse
Romans 3:10-12 There is no one righteous, not even one; there is no one who understands; there is no one who seeks God. All have turned away, they have together become worthless; there is no one who does good, not even one.