Joyce Landorf's book Irregular People is a wonderful tool to help us realize that sometimes there are others in life that are difficult to get along with no matter what we may say or do. This is a must read self-help book. Another book of Landorf's that is good is Balcony People. I love her theory of us always being Balcony People. :) We all need to be the type of people that gives encouragement to others. (Balcony People)
Understand the nature of your irregular person--why he or she behaves in that maddening way; develop strategies for coping; handle negative emotions such as anger, frustration, and bitterness; and keep forgiveness and reconciliation active in your life.