ANGER

It is a God-given emotion. 

If the Lord hates sin, His people should hate sin. If evil arouses His anger, it should arouse ours also. What other reaction can wickedness provoke in those who love God ... (especially when it appears in one's own life). 

Indignation has taken hold of me because of the wicked, who forsake Your law. Psalm 119:53

Christ's righteous anger was on display when He cleansed the Temple ...

And Jesus went into the temple of God, and cast out all them that sold and bought in the temple, and overthrew the tables of the moneychangers, and the seats of them that sold doves, And said unto them, It is written, My house shall be called the house of prayer, but ye have made it a den of thieves. Matthew 21:12-13

In this day and age, people tend to condone iniquity in the name of 'love' or 'open-mindedness' ... but God never does. In the face of blatant evil, we should be indignant not tolerant, angry not apathetic. When Christians fail to feel or express anger, they unwittingly encourage sin. 

Be ye angry, and sin not: let not the sun go down upon your wrath: Ephesians 4:26

We must be aware that there is a type of anger that can rise from our latent 'sin nature'. Do not allow pride, arrogance, or resentment to corrupt a wave of 'righteous anger' prompted by the Holy Spirit. Believers should be angry at the things which anger the Lord (and for the same reason). 

Spurgeon - To be angry against sin is a high and holy thing.

You may find it difficult to practice true holy anger because human emotions are tainted by a limited worldview. God sees everything clearly and knows everything completely ... you do not. 

Therefore walk circumspectly, dear one. 

We can have anger toward sin and yet show grace toward those steeped in it ... (you were of that fold once, pilgrim).