I ran across this quote in a bible study I'm doing.  It's from the book, "Having a Mary Spirit" by Joanna Weaver.

Bitterness is like drinking poison and waiting for the other person to die.

It just struck me as incredibly perceptive.  It feels like everything I've been reading or hearing lately keeps coming back to the same conclusion.  Gratitude is the healthiest emotion you can have.  It has all kinds of beneficial health effects including boosting your immune system.  On the other hand, ingratitude or unforgiveness are very negative emotions and actually hurt you both physically and emotionally.

So if you have someone in your life that you need to forgive - do it today!  It will benefit you and also your relationship with God.