When I feel angry about something (even if I think it is "righteous anger"), I think of this quote and try to eliminate the contention right away. It is true that a contentious spirit really does affect all areas of our lives in a negative way.
QUOTE: If Satan can succeed in creating in us habits of arguing, quarreling, and contention, it is easier then for him to bind us with the heavier sins which can destroy our eternal lives. A contentious spirit can affect almost any phase of our lives. An angry letter written in haste can haunt us—sometimes for years. A few ill-advised words spoken in hate can destroy a marriage or a personal friendship, or impede community progress. ~Elder Marvin J. Ashton