Holy Bible Online 
The words we speak are a direct reflection of what's in our hearts. Understanding this biblical truth helps us align our actions with God's will, revealing the true nature of our faith.
You brood of vipers, how can you who are evil say anything good? For the mouth speaks what the heart is full of.
- Matthew 12:34 NIV
Brood of vipers! How can you, being evil, speak good things? For out of the abundance of the heart the mouth speaks.
- Matthew 12:34 (New King James Version - NKJV)
Ye offspring of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.
- Matthew 12:34 (American Standard Version - ASV)
You brood of snakes! How could evil men like you speak what is good and right? For whatever is in your heart determines what you say.
- Matthew 12:34 (New Living Translation - NLT)
O generation of vipers, how can ye, being evil, speak good things? for out of the abundance of the heart the mouth speaketh.
Matthew 12:34 (King James Version - KJV)
These versions all emphasize that the words someone speaks reflect the condition of their heart, with the metaphor of a "brood of vipers" used to describe those whose words and actions are corrupt.
Understanding the Meaning of "The Mouth Speaks What the Heart Is Full Of"
It’s impossible to harvest good fruit from bad trees. A heart that feeds on evil things is reflected in words and actions. No matter how hard one tries to disguise it, the mouth speaks what the heart is full of.
When Jesus spoke these words, He was referring to both good and bad things. A heart that feeds on the Word of God reflects its source - no matter how shy it may be:
You are the light of the world. A town built on a hill cannot be hidden.
- Matthew 5:14
Now, if your heart is focused on the pleasures of the world - no matter how much you try to control your words - eventually your heart will be revealed through them. That’s why serving God isn’t just about claiming to be a servant; sowing isn’t just about saying you sow.
As the body without the spirit is dead, so faith without deeds is dead.
- James 2:26
May your mouth be a good reflection of your heart, and may your heart be filled with the Spirit of God. Seek and strive to fill your heart with the Word of God. May your mouth sow good faith, and may there be an abundant harvest through your deeds.
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