Who is a fool?  After meditating upon these Scriptures you will know…

Pr 29:11 A fool gives full vent to his spirit, but a wise man quietly holds it back.

Pr 12:15 The way of a fool is right in his own eyes, but a wise man listens to advice. 16 The vexation of a fool is known at once,
but the prudent ignores an insult.

Pr 18:2 A fool takes no pleasure in understanding, but only in expressing his opinion.

Eccl 7:9 Be not quick in your spirit to become angry, for anger lodges in the bosom of fools.

Mark 7:20 And (Jesus) said, “What comes out of a person is what defiles him. 21 For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery,  22 coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. 23 All these evil things come from within, and they defile a person.”

Luke 12:19 And I will say to my soul, Soul, you have ample goods laid up for many years; relax, eat, drink, be merry.’ 20 But God said to him, ‘Fool! This night your soul is required of you, and the things you have prepared, whose will they be?’ 21 So is the one who lays up treasure for himself and is not rich toward God.”

Ro 1:21 For although they knew God, they did not honor him as God or give thanks to him, but they became futile in their thinking, and their foolish hearts were darkened. 22  Claiming to be wise, they became fools, 23 and exchanged the glory of the immortal God for images resembling mortal man and birds and animals and reptiles.

1 Cor 1:20 Where is the one who is wise? Where is the scribe? Where is the debater of this age? Has not God made foolish the wisdom of the world? 25 For the foolishness of God is wiser than men… 27 God chose what is foolish in the world to shame the wise; God chose what is weak in the world to shame the strong; 28 God chose what is low and despised in the world, even things that are not, to bring to nothing things that are, 29 so that no human being might boast in the presence of God.

Eph 5:3 But sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints. 4 Let there be no filthiness nor foolish talk nor crude joking, which are out of place, but instead let there be thanksgiving.  15  Look carefully then how you walk, not as unwise but as wise, 16  making the best use of the time, because the days are evil. 17 Therefore do not be foolish, but understand what the will of the Lord is.

Titus 3:9 But avoid foolish controversies, genealogies, dissensions, and quarrels about the law, for they are unprofitable and worthless. 10 As for a person who stirs up division, after warning him once and then twice, have nothing more to do with him, 11 knowing that such a person is warped and sinful; he is self-condemned.

1 Peter 2:15 For this is the will of God, that by doing good you should put to silence the ignorance of foolish people.