"You can learn to trust someone perfectly--but that's risky. Even highly trustworthy people can always change. You can most probably, but not certainly, trust people if they have been regularly honest up to now. That is, if they are not too emotionally disturbed and if they subscribe to usual moral rules.
Even when you cannot trust some people, you can teach yourself to feel only healthily sorry and disappointed about their behavior but not unhealthily enraged and self-pityingly about them as persons. Trust yourself to stop damning people as a whole, no matter how badly they now behave. Then you may--yes, may--help them to become more trustworthy."
After an affair, or an equally disturbing revelation, most of us don't want the truth. We ask for reassurances from the very person who was dishonest with us. We demand details that are often torturous.
We may "police" them, looking for signs of straightforwardness. The way back to trust is counterintuitive: The issue is whether we can trust ourselves to make wise decisions.
We can ask, Can I, and do I, want to be with this person? Will I be honest about my thoughts and feelings? Will I take the risk to further this relationship, knowing I cannot control the other? What would I do if my partner chose to, once again, be dishonest with me?
Hurt does not heal instantly, but it can calm us to look into ourselves and see our real choices."