Matthew 15:19

For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, railings.

Acts 8:22

Repent therefore of this thy wickedness, and pray God, if perhaps the thought of thy heart may be forgiven thee.

Matthew 5:28

But I say unto you, That whosoever looketh upon a woman to lust after her, hath already committed adultery with her in his heart.

Matthew 9:4

And Jesus seeing their thoughts said, Why think ye evil in your hearts?

2 Corinthians 10:5

Destroying reasonings, and every high thing which exalteth itself against the knowledge of God, and bringing every thought into captivity to the obedience of Christ,

Treasury of Scripture Knowledge

Summary

The thought of foolishness is sin: and the scorner is an abomination to men.

Bible References

Thought

Matthew 5:28
But I say unto you, That whosoever looketh upon a woman to lust after her, hath already committed adultery with her in his heart.
Matthew 9:4
And Jesus seeing their thoughts said, Why think ye evil in your hearts?
Matthew 15:19
For out of the heart proceed evil thoughts, murders, adulteries, fornications, thefts, false witness, railings.
Acts 8:22
Repent therefore of this thy wickedness, and pray God, if perhaps the thought of thy heart may be forgiven thee.
2 Corinthians 10:5
Destroying reasonings, and every high thing which exalteth itself against the knowledge of God, and bringing every thought into captivity to the obedience of Christ,