Romans 3
3 What, then, is the case? If some lacked faith, will their lack of faith invalidate the faithfulness of God?
4 Certainly not! But let God be found true, even if every man be found a liar, just as it is written: “That you might be proved righteous in your words and might win when you are being judged.”....
9 What then? Are we in a better position? Not at all! For above we have made the charge that Jews as well as Greeks are all under sin;
10 just as it is written: “There is not a righteous man, not even one;
11 there is no one who has any insight; there is no one who searches for God.
12 All men have turned aside, all of them have become worthless; there is no one who shows kindness, not so much as one.”
13 “Their throat is an open grave; they have deceived with their tongues.” “Venom of asps is behind their lips.”
14 “And their mouth is full of cursing and bitterness.”
15 “Their feet are swift to shed blood.”
16 “Ruin and misery are in their ways,
17 and they have not known the way of peace.”
18 “There is no fear of God before their eyes.”
Ecclesiastes 7:20
20 For there is no righteous man on earth who always does good and never sins.
Proverbs 20:9
9 Who can say: “I have cleansed my heart;I am pure from my sin”?
Proving God is true by men's righeousness is folly.