We are all human, which means we are imperfect people. People will hurt you. You will hurt other people. We have to stop hurting each other. It can only do us harm.
Friends are awesome. They say (I am still not sure who “they” are): When you get old you will be able to count your true friends on on hand. As Christians, we are called to fellowship with each other as friends.
So what happens when friends hurt one another or sin against one another? God commands us to love one another. When a transgression amongst friends happens, we are to seek out the matter with love and resolve it. Holding grudges and not forgiving only causes a divide. Forgive others as Jesus forgave us.