Jesus taught us how to be right in Relationships not just perform religious rituals – Matthew 5:21-26
Jesus shows us that the intent of the Law dealt with inner attitudes not just outward actions as the Pharisees had defined it. Angry attitudes and hurtful words damage people.
Sinful anger devalues a person who is created in the image of God (Genesis 1:26; 9:6); thus every person deserves our respect as they bear the image of God Himself.
Unconfessed and unchecked sinful anger can lead to killing people with our tongues and even murder. God warned Cain about his anger (it is "like sin crouching at the door") and it led to the murder of his own brother. (Genesis 4:5-9) Scripture warns us to "not let the sun go down while you are still angry, and do not give the devil a foothold." (Ephesians 4:26b-27) Unconfessed and unrepented of anger gives Satan an opportunity to make it worse so we need to repent of it quickly.
So deal quickly with the anger that comes about through relational conflicts versus holding a grudge for days (and even years) and letting the anger build. How to do this:
1) When offended by someone speak the truth in love to the person (not talk to others behind their back) versus holding a grudge. Do this by using "I" language versus "you" language, i.e., reporting your feelings versus blaming the offender for them. "I feel upset" or "I feel hurt" or "I’m getting angry", rather than, "you make me so mad" etc. This gives the offender an opportunity to see his possible fault and repent.
2) Forgive quickly. If the offender doesn’t think he is wrong and you have expressed your feelings directly to them your next move is to forgive.
There are consequences for sinful anger. The "judgment" (v.23) could be the local religious authorities or God’s final judgment. "But I tell you that men will have to give account on the day of judgment for every careless word they have spoken." (Matthew 12:36) This verse is speaking of the Pharisees’ blasphemous words against Jesus but every sinful word that we have not repented of will be judged by God.
To call a person "Raca" (empty-headed) or "you fool" (moron) is self-righteous, censorious judgment and strips a person who is made in the image of God of their personal identity and makes them into something they are not.
Relationships with people affect our relationship with the Lord and vice versa. Jesus was speaking to his disciples in Galilee and telling them that if they went all the way to the temple in Jerusalem to offer a gift to God (in order to be right with Him) and yet remember that we have wronged someone, that we need to go all the way back to Galilee first to make amends with the wronged person and then come back to Jerusalem to "get right with God". The point here is that God puts an urgency and high priority on our relationships with other people. Remember the high priority God put on reconciled relationships – the death of His Son.
"If anyone says, "I love God," yet hates his brother, he is a liar. For anyone who does not love his brother, whom he has seen, cannot love God, whom he has not seen." 1 John 4:20
Example from the cross: If the horizontal (relationships with people) is out of line then the vertical (our relationship with the Lord) will be out of line. (Also see 1 Peter 3:7 for husbands and wives)
Jesus tells us to work urgently and harder on building and maintaining right relationships than on working hard to get our way. And Jesus practiced what He preached – all the way to Calvary. And remember as we behold Him (His example of how to live and relate) and yield to the Holy Spirit we will be changed into His image, His character and His ways from one degree of His likeness to another thus bringing glory and honor to our great God. (See 2 Corinthians 3:18)