I know from personal experience and pastoral ministry that the quickest way to kill happiness is by living in sin. This seems especially true with sinful anger.
Jonathan Edwards preached a series of sermons on 1 Cor 13. Here is what he said about anger and its joy-killing capacity,
How such undue anger destroys the comfort of him who indulges in it. It troubles the soul in which it is, as a storm troubles the ocean. Such anger is inconsistent with a man’s enjoying himself, or having true peace or self-respect in his own spirit. Men of an angry and wrathful temper, whose minds are always in a fret, are the most miserable sort of men, and live a most miserable life; so that a regard to our own happiness should lead us to shun all undue sinful anger.
—Charity Contrary to an Angry Spirit
Want to be miserable and not enjoy life? Then stay angry. Want to live in happiness, have self-respect, and true peace? Then work hard at shunning all undue sinful anger. It may really be that simple.
“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.”
(Jas 1:19-20 ESV).
*photo taken from pixabay.com