Righteous and Unrighteous Anger

Baxter:

Anger is the rising up of the heart in passionate displacency against an apprehended evil, which would cross or hinder us of some desired good. It is given us by God for good, to stir us up to a vigorous resistance of those things, which, within us or without us, do oppose his glory or our salvation, or our own or our neighbor's real good. 

Anger is good when it is thus used to its appointed end, in a right manner and measure; but it is sinful, 1. When it riseth up against God or any good, as if it were evil to us. . . . 2. When it disturbs reason, and hindereth our judging of things aright. 3. When it casteth us into any unseemly carriage, or causeth or disposeth to any sinful words or action: when it inclineth us to wrong another by word or deed, and to do as we would not be done by. 4. When it is mistaken, and without just cause. 5. When it is greater in measure than the cause alloweth. 6. When it unfitteth us for our duty to God or man. 7. When it tendeth to the abatement of love and brotherly kindness, and the hindering of any good which we should do for others: much more when it breedeth malice, and revenge, and contentions, and unpeaceableness in societies, oppression of inferiors, or dishonouring of superiors. 8. When it stayeth too long, and ceaseth not when its lawful work is done. 9. When it is selfish and carnal, stirred up upon the account of some carnal interest, and used but as a means to a selfish, carnal, sinful end: as to be angry with men only for crossing your pride, or profit, or sports, or any other fleshly will. In all these it is sinful.

—Richard Baxter, A Christian Directory (vol. 1 in The Practical Works of Richard Baxter; Morgan, PA: Soli Deo Gloria Publications, 200), 284.