Matthew 12:33-37 – “Either make the tree good and its fruit good, or make the tree bad and its fruit bad; for the tree is known by its fruit.  34 ” 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.”  NASB

I have heard so many interpretations of verses 36-37 that I approach this with great caution and careful thought.  I have had people tell me that this means that if you are not talking about God all the time you are uttering idle or careless words and will be judged for it.  That would seem quite legalistic and be quite a prison for all of us.  I am not sure how you would conduct business, develop a social life, find a mate, or train your children in all aspects of life under that interpretation but if that is your view so be it.  I would ask that you restrain yourself in seeking to impose it on the rest of us. 

I have studied this troubling and seemingly difficult translation to find what our Lord was truly saying to those in his audience then and now.  I refer you to two notable commentators on Scripture:

Adam Clarke suggested:

 [Every idle word] – Reema (NT:4487) argon (NT:692), a word that does nothing, that neither ministers grace nor instruction to them who hear it.  The word argon (NT:692) corresponds to the Hebrew shaaw’ (OT:7723), which signifies not only vain or empty but also wicked and injurious, such as a false testimony against a neighbor, compare this to Deut 5:11 and 20.

Add to this, that Symmachus translates piguwl (OT:6292), polluted, Lev 19:7, by the very Greek word in the text. It was to explain this ambiguous meaning of the word, that ten MSS, have changed argon (NT:692), into poneeron (NT:4190), evil. Our Lord must be understood here as condemning all false and injurious words: the scope of the place necessarily requires this meaning.

In looking at verse 37 we realize that – [By thy words thou shalt be justified] That is, the whole tenor of thy conversation will be an evidence for or against thee, in the great day.  How many are there who count words for nothing! and yet eternity often depends on them. Lord, put a watch before the door of my lips! is a prayer proper for all men.

Barnes Notes suggested:

[But I say unto you …] Christ closes this address to his malignant and wicked hearers by a solemn declaration that for these things God would bring them into judgment. Therefore. They who had spoken so malignantly against him, could not escape.

[Idle word] This literally means a vain, thoughtless, useless word; a word that accomplishes no good. Here it means, evidently, “wicked, injurious, false, malicious, for such” were the words which they had spoken.

[By thy words thou shalt be justified …] That is, “words” are the indication of the true principles of the heart; by “words” the heart shall be known, as the tree is by its fruit. If they are true, proper, chaste, instructive, and pious, they will prove that the heart is right. If false, envious, malignant, and impious, they will prove that the heart is wrong, and will therefore be among the causes of condemnation. It is not meant that words will be the only thing that will condemn man, but that they will be an important part of the things for which he shall be condemned. See James 3:3-12.

I would suggest that Jesus is referring to words that are “without value,” words that are “harmful,” and words that are “untrue.”  I would also suggest that He is identifying the condition of the heart referring to the utterance of words and is telling all who will hear that it is a Wholesome, God-FearingLife that is to be prized and that will be acceptable to God on that day. 

To suggest that simply constructing our language and conversation in a particular way would be enough to gain entrance into Heaven would be to trample under-foot the Blood of Jesus and slander the Grace of God.  It would make Grace something earned and Salvation something we can become worthy of by our actions or words, and we know that is not according to Scripture. 

Therefore, this cannot be interpreted in that manner so understanding that it is not just talking about a particular dogma that our Lord is focused on but the Whole of Our Lives and instructing us to understand that “Words Have Meaning” and are “Powerful.”   I too pray that God places a guard at my mouth and my heart.

May God be with you as you go through your day.