It would be great if everyone in the world were honest. We wouldn't be think of people, who want to fool us and make profit of our misery. Well, let's hope, that one day it will arrive, and for now find out how to deal with dishonest people.
Be conscious about dishonest people. Being conscious about the thing that some people in your circle are dishonest, won't let them fool you. Once you learn that someone tries to manipulate you, try to find the way how you can stay in the high consciousness state. For instance, it can be meditation. Spend just five or ten minutes a day for meditation, and you can block the negative energy that dishonest people send you.
No “an eye for an eye”. It's understandable that you'd like to treat the dishonest people the same way they treat you or others. But actually this won't work. Dishonest people are always aware that someone wants to fool them too. They know their pattern of behavior and subconsciously project it to others. And since they are always waiting for something foul, it's very hard to punish them.
Try to treat dishonest people honestly. Being direct, kind and honest with dishonest people will help you to raise their consciousness. Now you're the example to follow, so show how you want others treat you. It's kind of the message you send to others, and by this message you tell them how you want to be treated. It's great if you see some positive changes. Even negative changes are also good (for instance, this person reacts with resistance to your kind behavior). But if you see that this person is always in a neutral state and shows no reaction to your behavior, then you need to consider the following tip.
Think of an ultimatum. Ultimatum can be used only in several cases. If the dishonest party is not receptive to your approaches, you're concerned about the well-being of that person or their dishonest behavior affects both of you in a negative manner. Unfortunately, even ultimatums don't always help in such situations. So if you see that the dishonest person never changes, then it's time to get ready for the most drastic measures.
Leave the person behind. Whether it's your friend, colleague or a second half, who is dishonest with you, you don't have to suffer in order to keep the relations. There are many honest people in the world and you can meet them. Be prepared to cut the dishonest person away from your life. Whether it's reducing contact with the person (if it's your friend) or an official ending of the relationship, you need this step, otherwise nothing will help you reduce the impact of the dishonest person on your life.