Often in our day if we tell the truth about a matter in a kind and friendly way, someone hearing is going to be angry and others will judge us as having been rude because the other person became angry.
This is backward, just because someone became angry at what we said does not mean we caused their anger. Jesus Christ and the apostles experienced this irrational anger all the time with those who didn't want to hear the truth.
There is a difference between righteous anger and fleshly anger. Fleshly anger is usually associated with self-esteem, someone doesn't like to hear the truth about themselves so defensiveness emerges to stop the criticism. Manipulative rage is designed to make the truth-teller feel guilty. It is common in our culture to judge someone as rude and causing anger in someone else merely by telling the truth or asserting our boundaries.
However righteous anger is associated with injustice to someone else, or blasphemy against God and often anger at sin because of the destructive nature of sin.
Ephesians 4:26-27
"26 Be angry, and yet do not sin; do not let the sun go down on your anger, 27 and do not give the devil an opportunity."
Proverbs 22:24-25
"Make no friendship with an angry man; And with a furious man thou shalt not go: Lest thou learn his ways, And get a snare to thy soul."
James 1:19-20
“Let every person be quick to hear, slow to speak, slow to anger; for the anger of man does not produce the righteousness of God."
Anger in our culture is used to foster guilt in someone who speaks the truth. Manipulation in the form of rage is the favored tactic of the devil in the person he is using.
When we see this irrational anger of manipulation we would do best to ignore it and walk away. Never apologize for someone else's anger it only validates their strategy to control you and the conversation. As we keep ourselves calm and kind we do not have to be provoked ourselves by their choice to become angry.
1 Corinthians 13:4–8a "Love is patient and kind; love does not envy or boast; it is not arrogant or rude. It does not insist on its own way; it is not irritable or resentful; it does not rejoice at wrongdoing, but rejoices with the truth."
There are those who will call you unloving for obeying God, remember it is only a tactic that we need not take seriously or personally.