Psalms 5:9

5:9 For they do not speak the truth;

their stomachs are like the place of destruction,

their throats like an open grave,

their tongues like a steep slope leading into it.

Proverbs 20:5

20:5 Counsel in a person’s heart is like deep water,

but an understanding person draws it out.

Isaiah 29:15

29:15 Those who try to hide their plans from the Lord are as good as dead,

who do their work in secret and boast,

“Who sees us? Who knows what we’re doing?”

Jeremiah 17:9-10

17:9 The human mind is more deceitful than anything else.

It is incurably bad. Who can understand it?

17:10 I, the Lord, probe into people’s minds.

I examine people’s hearts.

I deal with each person according to how he has behaved.

I give them what they deserve based on what they have done.

Jeremiah 17:1

17:1 The sin of Judah is engraved with an iron chisel

on their stone-hard hearts.

It is inscribed with a diamond point

on the horns of their altars.

Colossians 4:5

4:5 Conduct yourselves with wisdom toward outsiders, making the most of the opportunities.