John the Baptist called the people of Judea “vipers” who came to him for baptism of repentance for the forgiveness of sins.  (See Luke 3:3)

(NASB) Luke 3:7 “So he began saying to the crowds who were going out to be baptized by him, ‘You brood of vipers, who warned you to flee from the wrath to come?’”

To be called a viper is not flattering and it is condemning.
The dictionary’s definition of Vipers: Any of various venomous Old World snakes of the family Viperidae; especially, a common Eurasian species.
Viperous: venomous; spiteful; malicious
John warned the viper’s of Judea of God’s wrath and their need to repent.

During Jesus’ ministry He also used the term “vipers” for the religious leaders of Israel.
(NASB) Matthew 12:34-37 “You brood of vipers, how can you, being evil, speak what is good?  For the mouth speaks out of that which fills the heart.
35 ‘The good man brings out of his good treasure what is good; and the evil man brings out of his evil treasure what is evil.
36 ‘But I tell you that every careless word that people speak, they shall give an accounting for it in the day of judgment.
37 ‘For by your words you will be justified, and by your words you will be condemned.’”

Your words will reveal what is in your heart, your treasure chest, good or evil.  Notice that Jesus did not say ‘bad’ He said ‘evil’!
You and I will be held accountable for our words on the Day of Judgment.  We will either be justified or we will be condemned.

Jesus spoke to Israel’s religious leaders in condemnation on another occasion.
(NASB) Matthew 23:33 “You serpents, you brood of vipers, how will you escape the sentence of hell?”

Jesus never, ever spoke lightly of good and evil.  He spoke from His true knowledge.  There will be a Day of Judgment and every person will be judged, held accountable for their choices, their words and their actions.  (See Revelation 20:11-15)

If religious leaders are held accountable, how can anyone escape the judgment of God?  If Jesus were to talk to you this day (and He does through His word, the Holy Bible); would He call you a viper?
Are your thoughts and words viperous: venomous; spiteful; malicious?

Through faith in Christ Jesus anyone will escape the wrath of God by repenting and asking Jesus to save them; only He can justify anyone before the living God.