From Beth Moore's Living Beyond Ourselves study (today is day 4 of week6--week's study is patience)....
To forgive in Greek is Aphiemi, which means to "let go from one's power, possession, to let go free, let escape", and the picture from the original Greek for unforgiveness is one in which the "unforgiven" is roped to the back of the unforgiving. So, the Greek meaning of forgiveness...is the practice of cutting loose the person roped to your back.

Beth Moore says that "it's difficult to live an effective Christian life with a body roped to your back." Leading back to Hebrews 12:1--How can I effectively run the race with perseverance that the Lord has set for me with the dead weight/body of unforgiveness on my back?! Boy, talk about a HINDRANCE!

She adds, "You cannot be free to keep step with the Spirit when you are encumbered by the load of unforgiveness." So, what else quenches and grieves the Spirit and keeps us from drawing near and being filled with the Spirit? UNFORGIVENESS!