user5689: How can I trust someone who lies, manipulates and hurts people? 
I know a person who manipulates people and I know I can not trust him but recently, the mother of that person has health problems, and my group of friends want to integrate him. I do not agree and now I have the impression of lacking compassion.
What should I do? Should I be more compassionate?

user5693: If one is truly giving, then there is no expectation of a response.  Not thankfulness, not appreciation, not acknowledgement, not response in kind.  The word "trust" invokes the sense that there is an expectation of some kind of reciprocity from the receiver of your giving.
Compassion is a form of giving.  In its true form it is not transactional. When one gives of oneself in some way, it is not for the benefit of the other, it is for the benefit of you.  When you give, what does it matter whether it is to a manipulative or "taking" person? The benefit accrues to you regardless.
The disingenuous person will perhaps require a long string of interactions before the epiphanous one that changes that person presents itself.

user-1: A person who has these tendencies is suffering greatly. He is causing great harm to himself and other beings by acting on the unwholesome roots of greed, anger and delusion. 
It does not really matter if you trust him or not. There is still the possibility that he could use or betray you. One cannot control reality. One is just given a hand of cards. It's up to oneself to find out how to play that hand in the most beneficial and wholesome way.
Let's look at both scenarios. 

You place your trust in him and he betrays you or uses you.

All he can do is to impinge on your sense-faculties. Anger can arise, sadness or other negative mind states can arise in you. That is really it. Noone can force you to react to these states of mind.
If you instead just observe them with mindfulness in the present moment then you can use these phenomena to cultivate insight. You can use them as a stepping stone to progress in your path.

You place you trust in him and he does not use or betray you.

This scenario is better for him since he does not create unwholesome kamma for himself since he is not doing those unwholesome actions.
For you it's pretty much the same. If happiness arises in you because of that you can enjoy that happiness without being attached to it. As long as you know it is impermanent and unsatisfactory you can enjoy it without dwelling in it. In the same way you can contemplate the conditioned happiness and see the danger in it if one gets attached to it. Conditioned happiness is dukkha in disguise because when it's exhausted it will leave behind a void leaving one wanting for more. That is if one is attached to the happiness. If not you can again use it for the cultivation of insights.
If you contemplate the situation you might find compassion for him. Why? Because he is dealing with the same "illness" that we are all dealing with, i.e. ignorance of the true nature of reality. We are all in the same boat here. Some beings minds are just clouded in a heavier darkness than others. When thinking about these beings naturally a deep compassion can arise.
We are all in this together. As long as we not enlightened we are all dealing with some level of ignorance meaning that we have a mind that is not fully trained to see reality clearly. Only the Buddhas and Arahants are fully awake.
By knowing that we are all in the same boat we can begin to view the situation in a different way.
I do not know if you are training in meditation at the moment but if you do and if you are practicing insight meditation (vipassana meditation) you will come to experience these things for yourself. By seeing this directly through observation of reality compassion can arise in you.
Buddhist ethics is centered on intentions / volitions. When acting according to the Noble Eightfold Path one should cultivate Right Intention (Samma Sankappa), i.e. intentions of renunciation, good will and harmlessness.
It is not your job to fix him or other people. By working on ourselves and purifying ourselves from defilements we can be good examples for other beings. Naturally people want to be around a person that is honest, wise, calm and peaceful.

user745: Being compassionate doesn't mean that you have to trust him or agree with what he is doing. Compassion (Karuna in Pali/Sanskrit) is defined as the wish that being be free from suffering.
If you see someone doing things that hurt other people, being compassionate in effect means that you want them to be free of the suffering they are undergoing. You don't have to trust them or let them walk all over you to be compassionate, so if you do let him join your circle of friends, you don't have to mistreat you or anyone else.
In fact, letting him mistreat others is actually the opposite of being compassionate because then they are only hurting themselves more. You need to be skillful in figuring out how to respond though. If you think that bringing it up to them would cause them to get defensive and just shut you out, then that would be a bad idea, but if you think you can get through to them in a way that won't cause more harm than good, then you should do that.

5689: <p>How can I trust someone who lies, manipulates and hurts people? </p>

<p>I know a person who manipulates people and I know I can not trust him but recently, the mother of that person has health problems, and my group of friends want to integrate him. I do not agree and now I have the impression of lacking compassion.</p>

<p>What should I do? Should I be more compassionate?</p>
 5693: <p>If one is truly giving, then there is no expectation of a response.  Not thankfulness, not appreciation, not acknowledgement, not response in kind.  The word "trust" invokes the sense that there is an expectation of some kind of reciprocity from the receiver of your giving.</p>

<p>Compassion is a form of giving.  In its true form it is not transactional. When one gives of oneself in some way, it is not for the benefit of the other, it is for the benefit of you.  When you give, what does it matter whether it is to a manipulative or "taking" person? The benefit accrues to you regardless.</p>

<p>The disingenuous person will perhaps require a long string of interactions before the epiphanous one that changes that person presents itself.</p>
 -1: <p>A person who has these tendencies is suffering greatly. He is causing great harm to himself and other beings by acting on the unwholesome roots of <em>greed, anger and delusion</em>. </p>

<p>It does not really matter if you trust him or not. There is still the possibility that he could use or betray you. One cannot control reality. One is just given a hand of cards. It's up to oneself to find out how to play that hand in the most beneficial and wholesome way.</p>

<p>Let's look at both scenarios. </p>

<ol>
<li><p>You place your trust in him and he betrays you or uses you.</p></li>
</ol>

<p>All he can do is to impinge on your sense-faculties. Anger can arise, sadness or other negative mind states can arise in you. That is really it. Noone can force you to react to these states of mind.</p>

<p>If you instead just observe them with mindfulness in the present moment then you can use these phenomena to cultivate insight. You can use them as a stepping stone to progress in your path.</p>

<ol start="2">
<li><p>You place you trust in him and he does not use or betray you.</p></li>
</ol>

<p>This scenario is better for him since he does not create unwholesome kamma for himself since he is not doing those unwholesome actions.</p>

<p>For you it's pretty much the same. If happiness arises in you because of that you can enjoy that happiness without being attached to it. As long as you know it is impermanent and unsatisfactory you can enjoy it without dwelling in it. In the same way you can contemplate the conditioned happiness and see the danger in it if one gets attached to it. Conditioned happiness is dukkha in disguise because when it's exhausted it will leave behind a void leaving one wanting for more. That is if one is attached to the happiness. If not you can again use it for the cultivation of insights.</p>

<p>If you contemplate the situation you might find compassion for him. Why? Because he is dealing with the same "illness" that we are all dealing with, i.e. <em>ignorance</em> of the true nature of reality. We are all in the same boat here. Some beings minds are just clouded in a heavier darkness than others. When thinking about these beings naturally a deep compassion can arise.</p>

<p>We are all in this together. As long as we not enlightened we are all dealing with some level of ignorance meaning that we have a mind that is not fully trained to see reality clearly. Only the Buddhas and Arahants are fully awake.</p>

<p>By knowing that we are all in the same boat we can begin to view the situation in a different way.</p>

<p>I do not know if you are training in meditation at the moment but if you do and if you are practicing insight meditation (vipassana meditation) you will come to experience these things for yourself. By seeing this directly through observation of reality compassion can arise in you.</p>

<p>Buddhist ethics is centered on <em>intentions / volitions</em>. When acting according to the Noble Eightfold Path one should cultivate <em>Right Intention (Samma Sankappa)</em>, i.e. intentions of renunciation, good will and harmlessness.</p>

<p>It is not your job to fix him or other people. By working on ourselves and purifying ourselves from defilements we can be good examples for other beings. Naturally people want to be around a person that is honest, wise, calm and peaceful.</p>
 745: <p>Being compassionate doesn't mean that you have to trust him or agree with what he is doing. Compassion (Karuna in Pali/Sanskrit) is defined as the wish that being be free from suffering.</p>

<p>If you see someone doing things that hurt other people, being compassionate in effect means that you want them to be free of the suffering they are undergoing. You don't have to trust them or let them walk all over you to be compassionate, so if you do let him join your circle of friends, you don't have to mistreat you or anyone else.</p>

<p>In fact, letting him mistreat others is actually the opposite of being compassionate because then they are only hurting themselves more. You need to be skillful in figuring out how to respond though. If you think that bringing it up to them would cause them to get defensive and just shut you out, then that would be a bad idea, but if you think you can get through to them in a way that won't cause more harm than good, then you should do that.</p>
