This from Terry Virgo’s blog:
When you go through hard times, bitterness is waiting at the door, offering you fellowship. ‘What a terrible time you’ve had,’ it says. ‘How cruel they’ve been! How unjustly you’ve been treated.’ But bitterness isn’t a friendly companion; it’s a vile weed which puts its roots down deep into people’s personalities. Not content to disfigure just one soul, it grows up searching for others who might be willing to draw near. If you yield to its offer of companionship, a root will grow in your soul and you’ll defile many others.
The only way to withstand bitterness is to make sure that you don’t miss the grace of God. Grace, like an effective weed-killer, can get to the root of bitterness and destroy its power. But you must deliberately obtain grace. You must make a specific choice to refuse bitterness, not once but many times. Bitterness will repeatedly knock on your door and you must always send grace to answer it . . .