When a person harbors hatred towards another individual, all that does is cause damage. It damages the one harboring the hatred, and in many instances, it damages the one who is the object of the hatred. If the person can overcome his natural inclination and get himself to forgive and release the negative feelings, it will bring blessing into his life and blessing into the other person's life. If we allow our sechel (logic)to take over our emotions, it would be obvious that we should forgive. Who wouldn't want blessing instead of damage?
A woman who we'll call Esther related: She was experiencing difficulties in having children. She tried many doctors, but none were able to help. She had a child many years ago, but has since then stopped. Through immense tefila and building of her emunah, Hashem led her to the place she needed to be to get her salvation.
Esther had a high school classmate named Sarah, who she met at a pidyon haben. She hadn't seen her in six years, and they began reconnecting. Sarah was a very good influence on Esther, religiously. She introduced her to her shemirat halashon group, and they learned various books together on the phone each night. One day, Sarah encouraged Esther to join a class given by a very inspirational speaker. Esther was excited to go, but when she found out the class was going to be held in the home of a different high school acquaintance of hers, who we'll call Leah, Esther immediately had flashbacks of all the times Leah bullied her in high school. She was also part of a group that laughed at her and called her names one summer in camp, and she did not want to be reintroduced to those memories. She politely told Sarah that the people at this class were not her type, and she didn't want to go. Sarah assured her that these ladies had the most beautiful middot, and she would really benefit from the class.
And with that, Esther agreed to try. The class was amazing, and the ladies there truly did have beautiful middot. Leah was so warm and kind, and she was a regular at hosting Torah classes. Esther realized this was not the same Leah that used to bully her in high school. She was a completely changed woman. Esther had a great conversation with Leah, and Leah even gave her encouragement and advice regarding tefila and emunah.
On the way home that night, Esther told Sarah how much she loved the class and all the ladies who attended. She then asked her about how many children Leah had, because she knew she got married around the same time as her. Sarah replied, "Unfortunately, Leah hasn't had any children yet after 8 years of marriage."
Esther was shocked and began thinking if perhaps her negative feelings towards her for all those years had something to do with it. When she got home that night, Esther began speaking to Hashem. She told Hashem she completely forgives Leah for everything she ever did to her. She released all of her negative feelings and begged Hashem to absolve her from all the things that she did to her when they were younger. From that day on, she began praying every day for Leah to have children. The next time she saw Leah was at a class four months later, and Leah had just announced that she was three months pregnant.
Esther was in tears. She felt that Hashem led her to meet up with Leah again after all these years just so she could forgive her. She wished Leah mazal tov, and Leah replied to her with the most beautiful beracha, saying that she should be blessed with a healthy pregnancy and a healthy baby.
Esther answered a loud Amen. She felt so close to Hashem at that time and asked Him to please use that beracha and give her a baby. Lo and behold, two weeks later, Esther took a pregnancy test, and it came out positive.
B'ezrat Hashem, both Esther and Leah should have healthy babies b'shaah tova. The zechut of forgiving and loving is enormous. The people who can get themselves to do it feel so much better about themselves, and they also bring so much blessing into their lives and the lives of the ones they forgive.