20 for a man's anger does not accomplish God's righteousness!
 21 So rid yourselves of all vulgarity and obvious evil, and receive meekly the Word implanted in you that can save your lives[2] 
 
Wisdom from Yacov/James:
 
Vs. 19b Let every person be quick to listen, but slow to speak...
 
There are times when  we need to learn the "Vocabulary of Silence", if we would listen more, our words would be words of the spirit and not of the flesh.    It takes much self control, to control the tonque, any married couple can tell you that, most fights would stop in five minutes, if we did not have to be the one to get the last word in, so before you know it a little disagreement turns into hurtful words and quarreling and even divorce.
 
Vs. 19 but be slow to anger

 

In other words do not be quick to speak when you have anger inside of you, that is when you need to walk away and calm down and pray.     The enemy loves to bring a spirit of strife into our marriages, family and Congregations, by being slow to anger we will not react in the flesh but let our words be filled with the wisdom and love of    G-d, and as we do this G-d's righteousness will prevail.

 
Vs. 20 for a man's anger does not accomplish God's righteousness.  

 

There is a difference between righteous anger. i.e. Yeshua's rebuke of the money changers in the temple, and His rebuke of certain Scribes and Pharisees, He was angered because of there total lack of respect for G-ds House of Prayer and for being hypocrites and because He knew that it was the spirit of saten behind their actions.
 
The anger in this verse is referring to bursts of anger, which can result in violence against another. It is an anger that acts before it thinks, and controlled by the passions and not the spirit.    We can be righteously angry at the works of the enemy and the sorrow he causes such as  war, poverty, sickness and bondage, but we need to walk in love with people.  We need to listen, and give a soft answer because  "A soft answer turns away wrath", your actions could  very well bring someone who has rejected G-d all of his life into a relationship with the Holy One of Israel, YHWH or turn him away.

 

 

 
Everymans Talmud p. 212, II "Brotherly Love"
 
R. Akiba said of the command, "Thou shalt love thy neighbor as they self (leve xix 18) that is was 'a fundamental principle of the Torah' His colleague, Ben Azzai, cited as a principle of still greater importance, "This is the book of the generations of Adam...in the likeness of God made He him' (Gen.v1) (Sifra as loc).  Universal love is here proclaimed not merely as the ideal advocated in the Torah but as the only true standard of human relationship.  While this first Rabbi referred to the explicit commandment, the second teacher based the ideal on the doctrine that all human beings are descended from one ancestor and are therefore bound together by the kinship of a common origin, and also that they share one inestimable privilege, viz of having been created in the divine likeness. 'With a solemn warning was the declaration made. "Thou shalt love thy neighbour as thyself" I (God) created him; and if you love him, I am faithful to repay you a good reward; but if you do not love him, I am the Judge to exact a penalty' (ARN xvi)."[3] (My Comment-I am only using these quotes as illustrations, it is not my intention to make them equal to scripture or the Words of Our Master Yeshua)
 
What did Our Master Yeshua Ha Mashiach have to say about this.....

 

 Luk 10:29 But he, wanting to justify himself, said to Yeshua, "And who is my 'neighbor'?"   Read Luke 10:29-37 for the answer

Mark 12:30-31
 
28 One of the Torah-teachers came up and heard them engaged in this discussion. Seeing that Yeshua answered them well, he asked him, "Which is the most important mitzvah of them all?" 29 Yeshua answered, "The most important is,
      'Sh'ma Israel, Adonai Eloheynu Adonai echad [Hear, O Israel, the LORD our God, the LORD is one], 30 and you are to love Adonai your God with all your heart, with all your soul, with all your understanding and with all your strength."
 31 The second is this:
      'You are to love your neighbor as yourself.'
There is no other mitzvah greater than these." 32 The Torah-teacher said to him, "Well said, Rabbi; you speak the truth when you say that he is one, and that there is no other besides him; 33 and that loving him with all one's heart understanding and strength, and loving one's neighbor as oneself, mean more than all the burnt offerings and sacrifices." 34 When Yeshua saw that he responded sensibly, he said to him, "You are not far from the Kingdom of God." And after that, no one dared put to him another sheilah.[4]