user2427: What is a Sangha?
I know that a sangha is group of Buddha’s followers!
But I want to have a more thorough understanding of what a sangha is!
Do you have to be a Buddhist to join a Sangha?

user625: What is a Sangha? says,

Sangha is the word used for a community of fellow practitioners in Buddhism. But a Sangha does not necessarily have to be Buddhist.
Thich Nhat Hanh, also called Thây, wrote in his recent book Good Citizens: Creating Enlightened Society the following text (it has been shorted for an abridged version):

It is difficult to make a change alone. In the Sangha there is a powerful collective energy of mindfulness and concentration. It can help us make a breakthrough; it ignites our insight. Our practice together of walking, sitting, breathing, eating, is very important. When we practice with the Sangha, it’s easier than practicing alone. Sometimes something may carry us away.
But thanks to the collective practice, we can regain our solidity. Even if we’re distracted, our Sangha can help us remember to come back to the present moment, to touch what is positive, to touch our own peace, to see how to undo the difficulty.
The Sangha doesn’t need to be Buddhist. Buddhism is made of non-Buddhist elements anyway. When I met Martin Luther King Jr., in 1966, we spoke about Sangha building. We spoke a few times about the beloved community. The beloved community is the Sangha.
In the Sangha there are those who bring happiness to many people. There are those who cook very well, and there are those who take care of the garden beautifully and grow nutritious vegetables. There are those who organize festivities in a very beautiful, creative way. There are those who don’t have these talents, but when they do sitting meditation they are very happy, and when they walk they are also very happy and this brings happiness to others. Such people are of great benefit to the Sangha.
Everybody contributes their part. You don’t need to be exactly like others. This is true whether you are thinking of your family as your Sangha or of the larger beloved community. Everyone has their own abilities.
You don’t need to be like others; you just need to be yourself. You don’t need to have perfect health or a perfect mind without any worries and anxiety. You can still have some pain in your body or some pain in your mind.
But thanks to the practice, you can create more joy, peace, and understanding that nourishes you, nourishes the Sangha, and nourishes the world.

The Sangha is therefore an important support in your practice. Thây considers it so important that he often says, the future Buddha is a Sangha.


The definition above is a quote from "the Wake Up community", which describes itself as including Buddhists and non-Buddhsts:

Wake Up: Young Buddhists and non-Buddhists for a Healthy and Compassionate Society
Wake Up is an active global community of young mindfulness practitioners, aged 18-35, inspired by the teachings of Zen Master and peace activist Thich Nhat Hanh. We come together to practice mindfulness (etc.)


user2427: 
Sangha is the word used for a community of fellow practitioners in Buddhism. But a Sangha does not necessarily have to be Buddhist.

It is difficult to make a change alone. In the Sangha there is a powerful collective energy of mindfulness and concentration. It can help us make a breakthrough; it ignites our insight. Our practice together of walking, sitting, breathing, eating, is very important. When we practice with the Sangha, it’s easier than practicing alone. Sometimes something may carry us away.
But thanks to the collective practice, we can regain our solidity. Even if we’re distracted, our Sangha can help us remember to come back to the present moment, to touch what is positive, to touch our own peace, to see how to undo the difficulty.
The Sangha doesn’t need to be Buddhist. Buddhism is made of non-Buddhist elements anyway.

In the Sangha there are those who bring happiness to many people.
There are those who cook very well, and there are those who take care of the garden beautifully and grow nutritious vegetables.
There are those who organize festivities in a very beautiful, creative way.
There are those who don’t have these talents, but when they do sitting meditation they are very happy, and when they walk they are also very happy and this brings happiness to others.

Such people are of great benefit to the Sangha.
Everybody contributes their part. You don’t need to be exactly like others. This is true whether you are thinking of your family as your Sangha or of the larger beloved community. Everyone has their own abilities.
You don’t need to be like others; you just need to be yourself. You don’t need to have perfect health or a perfect mind without any worries and anxiety. You can still have some pain in your body or some pain in your mind.
Source website- http://www.wkup.org/

user254: According to the Wikipedia article about Sangha,

It's a Pali word meaning meaning "association", "assembly," "company" or "community"
It usually means the monastic community of ordained Buddhist monks or nuns
As a separate category, those who have attained any of the four stages of enlightenment (for example Sotāpanna), are referred to as the ariya-sangha or "noble Sangha".
The word Sangha sometimes also includes laymen and laywomen who are personally dedicated to the discipline of Dharma-Vinaya
Some lay practitioners in the West these days use the word "Sangha" as a collective term for all Buddhists, but the Pali Canon uses the word parisā (Sanskrit, parisad) for the larger Buddhist community — the monks, nuns, lay men, and lay women who have taken the Three Refuges — reserving ‘Sangha’ for a more restricted use.

So according to these conventional (non-inclusive) definitions, only Buddhists (and of those, not all Buddhists) are in the "Sangha".

2427: <h3>What is a Sangha?</h3>
<p>I know that a sangha is group of Buddha’s followers!
But I want to have a more thorough understanding of what a sangha is!</p>
<p><strong>Do you have to be a Buddhist to join a Sangha?</strong></p>
 625: <p><strong><a href="http://www.wkup.org/what-is-a-sangha/" rel="nofollow">What is a Sangha?</a></strong> says,</p>

<blockquote>
  <p>Sangha is the word used for a community of fellow practitioners in Buddhism. But a Sangha does not necessarily have to be Buddhist.</p>
  
  <p>Thich Nhat Hanh, also called Thây, wrote in his recent book <em>Good Citizens: Creating Enlightened Society</em> the following text (it has been shorted for an abridged version):</p>
  
  <blockquote>
    <p>It is difficult to make a change alone. In the Sangha there is a powerful collective energy of mindfulness and concentration. It can help us make a breakthrough; it ignites our insight. Our practice together of walking, sitting, breathing, eating, is very important. When we practice with the Sangha, it’s easier than practicing alone. Sometimes something may carry us away.</p>
    
    <p>But thanks to the collective practice, we can regain our solidity. Even if we’re distracted, our Sangha can help us remember to come back to the present moment, to touch what is positive, to touch our own peace, to see how to undo the difficulty.</p>
    
    <p>The Sangha doesn’t need to be Buddhist. Buddhism is made of non-Buddhist elements anyway. When I met Martin Luther King Jr., in 1966, we spoke about Sangha building. We spoke a few times about the beloved community. The beloved community is the Sangha.</p>
    
    <p>In the Sangha there are those who bring happiness to many people. There are those who cook very well, and there are those who take care of the garden beautifully and grow nutritious vegetables. There are those who organize festivities in a very beautiful, creative way. There are those who don’t have these talents, but when they do sitting meditation they are very happy, and when they walk they are also very happy and this brings happiness to others. Such people are of great benefit to the Sangha.</p>
    
    <p>Everybody contributes their part. You don’t need to be exactly like others. This is true whether you are thinking of your family as your Sangha or of the larger beloved community. Everyone has their own abilities.</p>
    
    <p>You don’t need to be like others; you just need to be yourself. You don’t need to have perfect health or a perfect mind without any worries and anxiety. You can still have some pain in your body or some pain in your mind.</p>
    
    <p>But thanks to the practice, you can create more joy, peace, and understanding that nourishes you, nourishes the Sangha, and nourishes the world.</p>
  </blockquote>
  
  <p>The Sangha is therefore an important support in your practice. Thây considers it so important that he often says, <em>the future Buddha is a Sangha</em>.</p>
</blockquote>

<hr>

<p>The definition above is a quote from "the Wake Up community", <a href="http://www.wkup.org/about/" rel="nofollow">which describes itself</a> as including Buddhists and non-Buddhsts:</p>

<blockquote>
  <p>Wake Up: Young Buddhists and non-Buddhists for a Healthy and Compassionate Society</p>
  
  <p>Wake Up is an active global community of young mindfulness practitioners, aged 18-35, inspired by the teachings of Zen Master and peace activist Thich Nhat Hanh. We come together to practice mindfulness (etc.)</p>
</blockquote>
 2427: <blockquote>
<h2>Sangha is the word used for a community of fellow practitioners in Buddhism. But a Sangha does not necessarily have to be Buddhist.</h2>
</blockquote>
<p>It is difficult to make a change alone. In the Sangha there is a powerful collective energy of mindfulness and concentration. It can help us make a breakthrough; it ignites our insight. Our practice together of walking, sitting, breathing, eating, is very important. When we practice with the Sangha, it’s easier than practicing alone. Sometimes something may carry us away.</p>
<p>But thanks to the collective practice, we can regain our solidity. Even if we’re distracted, our Sangha can help us remember to come back to the present moment, to touch what is positive, to touch our own peace, to see how to undo the difficulty.</p>
<p><strong>The Sangha doesn’t need to be Buddhist.</strong> Buddhism is made of non-Buddhist elements anyway.</p>
<ul>
<li>In the Sangha there are those who bring happiness to many people.</li>
<li>There are those who cook very well, and there are those who take care of the garden beautifully and grow nutritious vegetables.</li>
<li>There are those who organize festivities in a very beautiful, creative way.</li>
<li>There are those who don’t have these talents, but when they do sitting meditation they are very happy, and when they walk they are also very happy and this brings happiness to others.</li>
</ul>
<p>Such people are of great benefit to the Sangha.</p>
<p>Everybody contributes their part. You don’t need to be exactly like others. This is true whether you are thinking of your family as your Sangha or of the larger beloved community. Everyone has their own abilities.</p>
<p><strong>You don’t need to be like others; you just need to be yourself.</strong> You don’t need to have perfect health or a perfect mind without any worries and anxiety. You can still have some pain in your body or some pain in your mind.</p>
<h2>Source website- <a href="http://www.wkup.org/" rel="nofollow noreferrer">http://www.wkup.org/</a></h2>
 254: <p>According to <a href="http://en.wikipedia.org/wiki/Sangha" rel="noreferrer">the Wikipedia article about Sangha</a>,</p>

<ul>
<li>It's a Pali word meaning meaning "association", "assembly," "company" or "community"</li>
<li>It usually means the <strong>monastic community</strong> of <strong>ordained Buddhist monks or nuns</strong></li>
<li>As a separate category, those who have attained any of the <a href="http://en.wikipedia.org/wiki/Four_stages_of_enlightenment" rel="noreferrer">four stages of enlightenment</a> (for example Sotāpanna), are referred to as the ariya-sangha or "noble Sangha".</li>
<li>The word Sangha sometimes also includes laymen and laywomen who are personally dedicated to the discipline of Dharma-Vinaya</li>
<li>Some lay practitioners in the West these days use the word "Sangha" as a collective term for all Buddhists, but the Pali Canon uses the word <em>parisā</em> (Sanskrit, parisad) for the larger Buddhist community — the monks, nuns, lay men, and lay women who have taken the Three Refuges — reserving ‘Sangha’ for a more restricted use.</li>
</ul>

<p>So according to these conventional (non-inclusive) definitions, only Buddhists (and of those, not all Buddhists) are in the "Sangha".</p>
