Your attitude affects every relationship in your life, and sometimes relationships will never get started in the first place because your attitude has built up walls. Walls that make it difficult for people to be around you.
Bad attitudes effect your marriage relationships, relationship with your kids, work, church and friends.
The thing that makes a bad attitude so destructive is that like a jar of water with the loose lid on it. A bad attitude is eventually going to spill out into some negative actions, destructive words and deeds.