Matthew 12:34-35

You brood of snakes! how can you, bad as you are, utter anything good? For the mouth says only what the heart is full of.

Luke 6:45

A good man, out of the good he has accumulated in his heart, produces good, and a bad man, out of what he has accumulated that is bad, produces what is bad. For his mouth says only what his heart is full of.

Matthew 15:19

For out of the heart come wicked designs, murder, adultery, immorality, stealing, false witness, impious speech.

Mark 7:21-23

For it is from inside, from men's hearts, that designs of evil come; immorality, stealing, murder, adultery,

Mark 14:38

You must all watch, and pray that you may not be subjected to trial. One's spirit is eager, but human nature is weak."

Hebrews 12:15

Be careful that no one fails to gain God's favor, or some poisonous root may come up to trouble and contaminate you all??16 some immoral or godless person like Esau, who sold his very birthright for one single meal.

James 1:14-15

When anyone is tempted, it is by his own desire that he is enticed and allured.

Treasury of Scripture Knowledge

Summary

Keep thy heart with all diligence; for out of it are the issues of life.

Bible References

Keep

Mark 14:38
You must all watch, and pray that you may not be subjected to trial. One's spirit is eager, but human nature is weak."
Hebrews 12:15
Be careful that no one fails to gain God's favor, or some poisonous root may come up to trouble and contaminate you all??16 some immoral or godless person like Esau, who sold his very birthright for one single meal.

For

Matthew 12:35
A good man, out of the good he has accumulated, brings out things that are good, and a bad man, out of what he has accumulated that is bad, brings out things that are bad.
Matthew 15:19
For out of the heart come wicked designs, murder, adultery, immorality, stealing, false witness, impious speech.
Mark 7:21
For it is from inside, from men's hearts, that designs of evil come; immorality, stealing, murder, adultery,
James 1:14
When anyone is tempted, it is by his own desire that he is enticed and allured.