Matthew 12:34
You children of snakes! Since you are evil, how do you expect to speak good things? For the mouth speaks what the heart is filled with.
Matthew 10:27
What I am telling you in the darkness [i.e., in obscurity], you tell it in the light [i.e., openly]. And what you hear [whispered] in your ear [you should] declare it from the housetops.
Matthew 28:18-20
Then Jesus came and spoke to them, saying, "I have been given all authority in heaven and on earth.
Mark 16:15
Then He said to them, "You [men] go into the entire world and preach the good news to every person.
Acts 18:9-10
Then the Lord spoke to Paul in a night vision [i.e., a divinely given dream]: "Do not be afraid, but speak up and do not hold [anything] back,
Romans 10:14-17
[But] how can they appeal to Him if they have not [first] believed in Him? And how can they believe in Him if they have not [first] heard [about Him]? And how can they hear [about Him] if there is no preacher?
Romans 15:18-21
For I will not dare to speak about anything, except what Christ has done through me in bringing about the obedience of the Gentiles. He accomplished this by my message and my deeds,
Ephesians 4:29
Do not allow unwholesome [Note: The Greek word for "unwholesome" is "rotten, diseased"] language to come from your mouth, but only what is helpful for building up those who need it, so that you can impart favor [i.e., benefit] to those who listen [to you].
2 Timothy 2:2
And the things that you have heard from me in the presence of many witnesses, you should pass on to trustworthy men who will be able to teach other people also.
James 3:6
And the tongue is [like] a fire [i.e., like that spark]. [For] the tongue, as a part of the body, is [like] the world of evil. It corrupts the entire life [of a person] and inflames the course of nature itself [i.e., it affects a person throughout his whole earthly existence], and is ignited by hell itself [i.e., the evil produced by the fiery tongue has hell as its source and destiny].