The Bible has a lot to say about anger.
I don’t mean righteous anger, the kind of anger we can experience toward injustice or evil but sinful anger. Many times we may feel we are “righteous” in our anger because someone wronged us. Anger often involves our sense of justice. But it’s very easy to slide into sinful anger, hatred, and bitterness. Here are some Biblical truths and principles that God has used to help me make progress in conquering my own sinful anger.
Anger is not caused by other people or our circumstances. It comes out of our own hearts.
For out of the heart come evil thoughts, murder, adultery, sexual immorality, theft, false witness, slander. MT 15:19
No one else can make you angry. Circumstances don’t cause your anger. Anger is your own sin. David Powlison says our hearts are like sponges. If I squeeze a sponge and black ink comes out, it might seem that the squeezing caused black ink to come out. Yet I might squeeze another sponge and have clear water come out. So, it was not the squeeze that caused the ink to come out, but ink came out because that was what was in the sponge. The squeeze merely revealed what was there in the first place. Other people and circumstances can “squeeze” our hearts and if anger comes out, it is because that’s what was in our heart.
Anger is caused by our own unfulfilled desires.
What causes quarrels and what causes fights among you? Is it not this, that your passions are at war within you? You desire and do not have, so you murder. You covet and cannot obtain, so you fight and quarrel. You do not have, because you do not ask. JA 4:1–2
James says our own “passions”—cravings and desires—cause all our quarrels and fights. We desire and do not have; so, we murder, fight, and quarrel. In other words, we want something and we don’t get it; so, we get angry. Whenever you are angry ask yourself, “What is it that I want right now that I’m not getting?” Once I told my kids to go to bed and heard them wrestling and throwing things upstairs. When I went up I said, “You’re making me mad,” to which one replied, “But you have said no one else can make you mad.” I said, “You’re right. You are disobeying me, which tempts me (squeezes me), and it is my anger, my sin.” When I went downstairs I asked myself, “What do I want that I’m not getting?” My answer: I wanted to relax. I wanted kids who always perfectly and immediately obeyed. I wanted to watch TV, not oversee bedtime.
Anger won’t make anyone do the right thing. 
Know this, my beloved brothers: 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. JA 1:19–20
Many times we think anger will motivate others to do the “right” thing. Parents think anger will make their kids do the right thing, or act “righteously.” But anger won’t produce the righteousness of God. Anger might make kids outwardly obey, like little Pharisees, but it won’t change their hearts. Anger won’t produce inward righteousness in our spouse or coworkers. Anger does no good.
Anger toward another person is murder of the heart.
“You have heard that it was said to those of old, ‘You shall not murder; and whoever murders will be liable to judgment.’ But I say to you that everyone who is angry with his brotherc will be liable to judgment; whoever insultsd his brother will be liable to the council; and whoever says, ‘You fool!’ will be liable to the hell of fire.” MT 5:21–22
We tend to downplay the seriousness of anger. “I was just venting” or “letting off steam.” But Jesus said anger is murder of the heart and a violation of one of the 10 commandments. It can make us subject to the very hell of fire.
Anger makes things worse. 
A harsh word stirs up anger. PR 15:1
A hot-tempered man stirs up strife. PR 15:18
Not only does anger fail to produce righteousness, it makes things worse. It stirs up anger in others. It stirs up strife. It has the opposite effect to what we are desiring.
Anger opens the door for Satan
Be angry and do not sin; do not let the sun go down on your anger, and give no opportunity to the devil. EPH 4:26–27
When we “let the sun go down on our anger” or fail to deal with it in a timely fashion, either by asking forgiveness, forgiving others, or working things out with them, it opens the door for Satan to tempt us to bitterness, revenge, slander, and a host of other sins. Cain’s anger at Abel led him to kill his brother. Anger is serious. We must deal with it quickly.
These truths have helped me numerous times when I’ve been tempted to anger.  I’m not saying I’ve conquered it and I never sin in anger. But by God’s grace, understanding these things has helped me make progress. I hope you, too, will find God’s Word and Spirit help you make progress in overcoming anger.
Mark Altrogge has been senior pastor of Sovereign Grace Church of Indiana, Pennsylvania, since 1982. He has written hundreds of songs for worship, including “I Stand in Awe” and “I’m Forever Grateful.” Mark and his wife, Kristi, have four sons and one daughter. Find out more on his blog, The Blazing Center.