Romans 3:13-14
[Psa. 5:9 says], "Their throats are like open graves [i.e., they are foul-mouthed]. They have spoken deceitfully." [Psa. 90:3 says], "There is snake venom under their lips [i.e., their words are deadly]."
James 3:5-9
So, the tongue is a small part [of the body], yet it boasts of great accomplishments. Look at how large a forest is burned up by even a tiny spark.
Revelation 21:8
But the place for cowards, and unbelievers, and disgusting people [i.e., because of their terrible sins], and murderers, and sexually immoral people, and sorcerers, and idolaters, and all liars, will be the lake that burns with fire and sulphur. This is the second death."