Just read a chapter in Erwin McManus's book Uprising about gratitude. McManus is kind-of wordy, but I've quoted a long portion of the chapter below because it's pretty insightful about how gratitude, forgiveness, optimism and wholeness are linked...
Forgiveness and gratitude are inseparable. When we receive forgiveness, we grow in gratefulness. When we grow in gratefulness, we are more willing to give forgiveness. Our ability to receive forgiveness is directly related to our willingness to give it. Beyond that our model for forgiveness is Jesus himself. Paul reminds us, “Bear with each other and forgive whatever grievances you may have against one another. Forgive as the Lord forgave you. And over all these virtues put on love, which binds them all together in perfect unity.
When we are grateful, we forgive freely. A direct benefit of gratitude is the freedom from bitterness. When we are grateful, we are not bound to grudges or vengeance. Gratitude enables us to be generous with love. Forgiveness is a significant part of this. When there is a deficit of love, there is also a reluctance to forgive. This is a significant dilemma for us in our journeys toward emotional well-being in that an unwillingness to forgive will circumvent the process of becoming whole.
In the same way that gratitude is intertwined with forgiveness, brokenness is often perpetuated by bitterness. It’s not that bitterness is the cause of our brokenness, but that bitterness will circumvent the healing process. What makes this even more complicate is that oftentimes a broken person is more than justified to be embittered. Sometimes when I hear the tragic stories and the horrific experiences others have gone through, it’s hard not to take on their offenses and become embittered with them. It’s not an easy thing to tell someone who has been deeply hurt that her own road to healing is to forgive those who hurt her.
Aside from the fact that offenders need forgiveness, to forgive is essential in the process of healing. You cannot remain embittered and find wholeness. Even when those who have hurt you neither seek forgiveness nor desire it, it is still necessary that we forgive. In a reminder that we should not grieve the spirit of God, the Scriptures call us to “get rid of all bitterness, rage and anger, brawling and slander, along with every form of malice. Be kind and compassionate to one another, forgiving each other, just as in Christ God forgave you” (Eph. 3:31-32). This passage beseeches us to replace bitterness with forgiveness. In a conversation between Peter and Simon the Sorcerer, Peter makes this assessment of Simon’s heart: “I see that you are full of bitterness and captive to sin” (Acts 8:23). When we forgive, it sets us and others free. Bitterness on the other hand holds us captive. When someone desires forgiveness, it is your gift to give out of the generosity of your spirit. Even if one does not desire your forgiveness, it is critical to be free from the bitterness that will enslave you.
Again, even as gratitude and forgiveness are inseparable, so are ungratefulness and bitterness. When we are grateful, we see and experience life with a healthy optimism. When we lack gratitude, we move toward pessimism and even cynicism. A ungrateful heart always see what’s wrong with life. The longer we live without gratitude, the more embittered we become. The more embittered we become, the more we find ourselves overwhelmed with depression. Bitterness in the end leads to hopelessness. If we are to enjoy lives of gratitude, we must break free from the gravitational pull of bitterness. For in the same way that gratitude leads to wholeness, bitterness will leave us shattered and broken. In this condition we will find ourselves unable to experience the life God dreams for us, and tat the same time we will leave others cut and bleeding as they press against our sharp edges.
Bitterness creates an illusion of control and power. Bitterness is a form of hate. It is anger facing backwards. When we are embittered toward someone, we hold him prisoner to an experience or action in the past. In our minds our bitterness hold him captive and does not allow him to move forward. The reality is that our bitterness traps no one but ourselves. If the offender genuinely seeks forgiveness, even when you are unwilling to give it, he or she is made free. The only person you keep trapped in yesterday when you are unwilling to forgive is yourself. If you remain bitter long enough, you will eventually move to despair. Bitterness requires that you live in the past; hope requires that you live for tomorrow. Gratitude not only allows you to enjoy the present, but keeps you looking forward to the future.