It's easy to pull a newly planted tree out of the ground but once it's had time to grow and take root, a fully grown tree is that much harder to remove. If we don't deal with inforgiveness and anger today, tomorrow it becomes bitterness, associated with negative emotion, stress and thoughts of revenge.
An example of this is Debbie Morris, the author of Forgiving the Dead Man Walking, the counterpart to the 1995 award-winning movie Dead Man Walking.
At age 16, Debbie and her boyfriend were abducted at gunpoint by Robert Willie and Joe Vaccaro. Her boyfriend was led into deserted woods, tortured, shot, and left for dead. Debbie was repeatedly raped by her captors. They both survived their ordeal, but Willie ended up on death row awaiting execution for the murder of another woman he had killed only days before - the basis of the movie Dead Man Walking.
Yet Debbie says, "I think that many times people in my situation think that justice is what is going to heal them - and I thought that ... and I was disappointed time after time ... Justice is not what heals us and it was not what healed me.
"I realised that there is no such thing as justice on this earth for what that man did ... When I was able to forgive, not only did the hate, the anger and the pain go away, but the shame did too."
Justice depends on the effectiveness of the legal system. Offenders also have to deal with their own conscience, the legacy of their life, and their judgment to come.
The movie industry knows us well and feeds our natural desire for revenge.
Take any action movie you have seen. The very basic theme is "good person" versus "evil person", and the final scene, after the evil person has been really evil, is the goodie walking away from a scene of pandemonium, fire, and destruction where the baddie has just been violently killed - the more violent, the better.
That's why forgiveness is so hard, it goes against the grain.
Mahatma Gandhi said "The weak can never forgive. Forgiveness is the attribute of the strong."
Yet we recall the line from the Lord's prayer, "Forgive us our sins as we forgive those who sin against us." Forgiveness comes back to us.
We can live in the bondage of bitterness or the freedom of forgiveness.
As Smedes says, "Forgiving does not erase the bitter past. A healed memory is not a deleted memory. Instead, forgiving what we cannot forget creates a new way to remember. We change the memory of our past into a hope for our future. It takes one person to forgive, it takes two people to be reunited".
Christmas is a great time to receive and offer forgiveness. It is an investment in family life that has great returns.
• Bob McCoskrie is national director of Family First NZ.