"The weak can never forgive. Forgiveness is the attribute of the strong." -Mahatma Gandhi
"It is more shameful to distrust our friends than to be deceived by them." -Confucius
So here you are. In a pit of despair. Lied to by the people that you trusted. Left in the cold by your friends. Your back is against the wall. You feel them holding your head underwater even though they are no longer there. The whole world seems to be moving along just fine without you. But you are hurt. You are enraged. You have been wronged. What should you do? Forgive.
To encounter betrayal is to know that you have truly loved and trusted another. It is the ultimate test of your faith. You believed so firmly in someone or something that you were willing to abandon any notion of serious harm. If we are alive and our hearts are open, we will all suffer betrayal. It is as essential to being human as walking on two legs. We see the earliest notions of betrayal in the process of parental discipline as we move from getting everything that we cried for as infants to learning that the world has limits and we are accountable to those limits. Small betrayals happen everywhere when we see them for what they actually are--unmet expectations.
With the evolution of the neocortex (the thinking part of the brain) came the never-ending process of categorization. Early humans developed language to sort the natural world into some form of order. Plants that look like this are edible, weather that feels like this is dangerous, these kinds of stones make good arrowheads, these kinds of relationships are comforting, and these types of people cannot be trusted. If it weren't for the human gift of codification we would be consumed by the darkness of chaos and probably would not have survived as a species. Without words, there are no colors in the landscape of the imagination. Without words, it is difficult to understand the complexities of cause and effect. Without words, there is no difference between right and wrong. Without words, there is no such thing as choice.
With choice comes the implicit understanding that we are responsible for choosing our reality, and this is no small responsibility. The categories and assumptions that we make about our world have great consequences on how we operate in that world. If we assume that the world is unsafe, then we will live in such a way that supports that belief (avoiding risk, overprotecting our belongings, etc.). If we think that everyone likes us and is looking out for us, then we are apt to behave naively, that is until we are sorrily dispossessed of that notion like we might be dispossessed of our valuables (or worse).
The point is not to distrust everyone, nor trust everyone either. The point is to adopt a mindset that most accurately reflects true reality. In reference to betrayal, we must not become complacent in our relationships, assuming that they are static. Relationships are alive, and anything that is alive needs attention to survive. Betrayal occurs when we stop tending to our relationships and they shift without us recognizing it. It's like we fell asleep in New York but woke up in Morocco. It is disorienting, but remember it was you who chose to go to sleep. So when you wake up you need to learn the native language, find the airport, and plan how you will reintroduce yourself to New York.
The word forgive has its roots in Latin and means "to give completely and without reservation." I would consider forgiveness the highest form of love possible. It may seem counterintuitive to give completely to the very people who betrayed you, but it is the only way to resolve the cycle. If you run away in anger or disdain, you are destined to repeat the same mistake. To learn from betrayal involves admitting your own hand (i.e. your assumptions) in the situation. Once you have done that, then you can begin to forgive those who have wronged you and make the steps to apply what you have learned. This may mean you need to set more realistic expectations, establish clearer boundaries, or start pulling your weight. Lastly, you must also forgive yourself. We all err. Through forgiving, we learn to give only the parts of our hearts that we are free to give. We learn that working through difficulties is far more virtuous than just giving up.