I am sorry. I have not said it is impossible to not be angry at people.
Yes, when you went by peterjens, you did say this. We had a very long conversation and you said it was impossible to never get angry or resent if you have to be around other people. This was why you came to the conclusion that anger in your heart cannot possibly be murder as Jesus said.
I have said anger is an appropriate response in certain circumstances.
Yes, you have said this also. This gets into whether it is WITH cause or WITHOUT cause. If you are angry at your brother WITHOUT cause, it is murder. So, for instance, if I am angry with a brother and resentful and trying to cut him with my words because he has been sharp and nasty with me, I only have cause to not forgive his debt IF I have never been guilty of anger, resentment and cutting someone with my words. And since I, of course, have done this, my cause disappears. This is why let he who is without sin throw the first stone is so crucial, along with "without cause."
I think you are extending legalism into emotional flare-ups?
No. It would be legalism to say I have always kept the law to not murder because I have never strangled anyone to death. To know that I am a murderer even though I have never physically strangled anyone to death is the opposite of legalism - the spirit and truth of the matter.
Is it a sin for a parent to be angry with their child?
Is it a sin for a teacher to be angry with a pupil?
Is it a sin for a husband to be angry with their wife or the wife with their husband?
Only if it is without cause. And "you hurt my feelings" is without cause unless you yourself have never hurt someone elses feelings.
You appear to be claiming this is murder? Please help me understand you reference points.
The reference points are these:
If you do not forgive, you will not be forgiven.
The man who has his debt forgiven by God who then demands payment from someone else instead of forgiving their debt will be thrown into prison until he pays the last farthing.
I say to you if you have anger in your heart without cause at your brother, you are guilty of murder and the judgement.
All of those reference points should make a man cry out to God to forgive him of his sins. They should cause him to hunger for true righteousness in his inner man. But if he cannot see his murder, he will not repent and ask for forgiveness. He will just claim to have always followed the law to not murder all of his life. (Which is legalism and is seeing the letter of the law but not the spirit.)