The best non-Jesus example of the proper handling of bitterness is Joseph. Yes, this is an outflow of what I've been studying lately. That's how this thing works.
Joseph had every reason to be bitter. Admittedly, he had many years to get over his bitterness (and often this is how long it takes us, too), but scripture gives no indication that it took him that long. He at least was not bitter toward God throughout his ordeal. That much is clear from what he said about the temptation by Potiphar's wife. He said he could not sin against GOD, not just that it was bad to do it.
But, by the time Joseph came into contact with his brothers, he was not bitter and looking for revenge. He had forgiven them and was eager to reconcile. How much harder was it to forgive family that had done such a horrible thing than it is for us to forgive a church or pastor? No church has never plotted to kill me and then acquiesced to only selling me into slavery. And, again, they aren't family! Yes, they are a Christian family, a community, but they aren't blood. You might expect this kind of treatment from acquaintances but not your own half-brothers. Yet Joseph showed only love, kindness, and forgiveness.
Now, don't tell me all the horrible things that Joseph did to his brothers when they finally met. Joseph had to know if his brothers had changed. He had to know if they could be trusted. We can forgive a person, but it doesn't mean we immediately trust them again. Broken trust is more arduously regained. If you go back and read the story, it was Judah that offered himself as surety for the life of Benjamin. Judah - the same one who had the idea to sell Joseph into slavery. This is change. This is when Joseph knew that his brothers had repented of their sin.
This is what we pray for in those that have hurt us. We pray for obvious change. If we have been mistreated, sinned against, we should pray for a change of heart of the one that has done the hurting and that there can be a future reconciliation.
This begs the question: Am I ready for reconciliation with those that have hurt me? No. Not yet. Even though I know that what they meant for evil, God meant for good, the wound is still too fresh and the repercussions of their decisions are still too immediate. My prayer is that reconciliation can one day be achieved, but not yet. As the title says, bitterness continued.