If I make a decision to forgive, is that sufficient to actually forgive?
We did a study in which we asked some of the participants to go only to our Decision Phase of forgiveness. We asked other participants to advance through our entire Process Model of Forgiveness, which includes the Work and Discovery Phases. Those who stopped at the Decision Phase did not achieve the same psychological benefits as those who went through the entire forgiveness program. This was expected because to decide to forgive is not the same as exercising the moral virtue of forgiveness in its entirety. Here is the reference to that research:
Al-Mabuk, R., Enright, R. D., & Cardis, P. (1995). Forgiveness education with parentally love-deprived college students. Journal of Moral Education, 24, 427-444.