Most of us are familiar with Paul's admonition in Ephesians 4:26,
"Be angry and sin not."
This command requires some thought for most moderns. Both verbs in the original language are in the imperative mode. We are not only told not to sin, but we are commanded to be angry.
This is actually a quotation from Psalm 4:4. Most of us are not aware of this because our English translations of Psalm 4:4 generally read "Stand in awe and sin not." But the New Testament quotes from the Septuagint*, the Greek translation of the Old Testament, which renders these words from the Hebrew, "Be angry." Modern English readers, with our many translations of Scripture, have an opportunity to understand something about translation that most readers down through the ages have not necessarily seen. Translating from one language to another can be complicated. The root of the Hebrew word in Psalm 4:4 means to tremble. It is used for trembling from great emotion, agitation, extreme awe, anger or fear. If your prayers are always calm, you are missing something.
This reminds me of Hebrews 5:7. "In the days of his flesh Jesus lifted up prayers and supplications with loud cries and tears." Like God the Father, Jesus was angry from time to time. He demonstrated it when He drove the money changers from the temple. He trembled with anger as He stood at the tomb of Lazarus. He was angry at the stubborn scribes and Pharisees who perverted the law of God.
We are not sure how to respond to this. We may want to reprimand the Lord. "Now Jesus, we mustn't get angry." But there are times when not getting mad is sin. Of course, anger can also be dangerously sinful. So how do we find the balance of sinless anger? And how do we keep the sun from setting on our wrath? We need to pray over our anger.
Psalm 4:4 completes the command, "Commune with your own heart on your bed, and be still." There are two applications of this. First, we need to commune with God. And we also need to talk to our own hearts in the presence of God.
We need to wrestle in prayer over the reason we are angry. Am I angry because something is wrong or because it offends me? I may need to repent of my reasons for being angry. But if something is truly wrong, if it perverts or destroys something holy, then I need to join God in anger. I also need to put what angers me into the hands of God. Until I have communed with God over something, I will not know what I should do about what angers me. And by praying I recognize that even if I need to act on something, God is the only one who can make things right.
*I believe this is always true, but I have never read this anywhere or traced it out myself.