Writing a letter to someone you feel has betrayed you often is an upsetting and gruelling task that involves painful emotions most people would rather forget. It also entails the laborious task of addressing a person who has hurt you, which takes strength and courage. In order for your letter to be effective, only write your opinion of what has happened and how that makes you feel. Do not blame or point fingers by using "You did this ... " statements, or the person in question may not even read all of your letter. Write from your heart and state in the letter very clearly that this is how you feel. Whether your letter resolves any issues or not, it is an important part of your healing process and just writing your feelings down will most likely make you feel better.
Sit down and reflect on why you feel this person has betrayed you before you start writing. It may help if you have family or friends to talk with about the circumstances and to provide you with support and encouragement.
Write down notes about the situation, how you feel about what has happened and why you feel betrayed by this person. These are just rough notes to use while you are writing the letter. Take your time to think about what you would like to say in your letter.
Begin writing your letter. Use "I" statements instead of "You" statements. For example, say "I feel betrayed because ... " instead of "You betrayed me because ... " Although you may feel extremely hurt and angry, this type of writing dissolves negative blame and won't make the other person feel you are verbally attacking them. Include all the information from your rough notes that you would like to share with the recipient.
Read over your letter once you have completed it to reflect on what you are trying to say to the person who has betrayed you. Check for errors and spelling mistakes.
Deliver the letter. Send the letter to the person via postal mail. You also could physically deliver it or have a friend give it to the recipient. Or, you may decide never to give the person the letter, but instead keep it for your personal records or destroy it.