Betrayal is one of the very difficult things to forgive. Especially if it is done by relatives. As the saying goes, who betrayed once, betrayed twice. To take revenge on such people is not worth it, they punish themselves, but trust too.
You should not trust a person who has already betrayed you once. If he did it, it means that he wanted it, so it was convenient for him. Sometimes it happens that after some time, life confronts you with traitors. One lesson to be learned here is to understand that people don't change. You should not be evil to communicate with such a person, and even more so to take revenge. Just keep it at a distance. Don't believe in his remorse and renewed friendships that he offers.
The most painful thing is when close people turn out to be traitors. Those from whom you do not expect a dirty trick. There is a feeling of deception and emptiness. Man is a weak being, and under the influence of feelings and instincts, in certain life situations, he begins to save himself. Self-sacrifice is inherent in few people.
The tendency to betrayal, like other vices, "sucks in", you do it once, and repeat later many times, at the first ups and downs of life. Such people are inherently weak. They are afraid of responsibility, difficulties, they want to avoid them. When the crisis passes, they come back and begin to “repent”.
However, even such people deserve to be forgiven. Because everyone makes mistakes, but the question of trust is clear here.