Ephesians 4:26 tells us ” Be ye angry, and sin not: let not the sun go down upon your wrath.”
Anger that is selfish, undisciplined, and vindictive is sinful. This kind of anger has no place in the life of a Christian. On the other hand, anger that is unselfish and based on a love for God and concern for others is commanded. This is righteous anger. Genuine love cannot help being angered at that which injures the object of that love.