Proverbs 10:11-14 (ESV)

The mouth of the righteous is a fountain of life, but the mouth of the wicked conceals violence. Hatred stirs up strife, but love covers all offenses. On the lips of him who has understanding, wisdom is found, but a rod is for the back of him who lacks sense. The wise lay up knowledge, but the mouth of a fool brings ruin near.

Ecclesiastes 8:16-17 (ESV)

When I applied my heart to know wisdom, and to see the business that is done on earth, how neither day nor night do one’s eyes see sleep, then I saw all the work of God, that man cannot find out the work that is done under the sun. However much man may toil in seeking, he will not find it out. Even though a wise man claims to know, he cannot find it out.

Ecclesiastes 7:5-6 (ESV)

It is better for a man to hear the rebuke of the wise than to hear the song of fools. For as the crackling of thorns under a pot, so is the laughter of the fools; this also is vanity.

Ecclesiastes 7:10-12 (ESV)

Say not, "Why were the former days better than these?" For it is not from wisdom that you ask this. Wisdom is good with an inheritance, an advantage to those who see the sun. For the protection of wisdom is like the protection of money, and the advantage of knowledge is that wisdom preserves the life of him who has it.

Ecclesiastes 5:15-16 (ESV)

15 As he came from his mother’s womb he shall go again, naked as he came, and shall take nothing for his toil that he may carry away in his hand. 16This also is a grievous evil: just as he came, so shall he go, and what gain is there to him who toils for the wind?

Ephesians 6:11, 14-17 (ESV)

Put on the whole armor of God, that you may be able to stand against the schemes of the devil... Stand therefore, having fastened on the belt of truth, and having put on the breastplate of righteousness, and, as shoes for your feet, having put on the readiness given by the gospel of peace. In all circumstances take up the shield of faith, with which you can extinguish all the flaming darts of the evil one; and take the helmet of salvation, and the sword of the Spirit, which is the word of God.

Matthew 7:15-20 (ESV)

"Beware of false prophets, who come to you in sheep’s clothing but inwardly are ravenous wolves. You will recognize them by their fruits. Are grapes gathered from thornbushes, or figs from thistles? So, every healthy tree bears good fruit, but the diseased tree bears bad fruit. A healthy tree cannot bear bad fruit, nor can a diseased tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Thus you will recognize them by their fruits."