Does religion necessarily create out-groups?

While taking a study break to read one of my favorite blogs, I came across a passage that seemed especially relevant to our class. I'll get to it in a minute.

First, a little disclosure. I'm a practicing Christian of an Eastern Catholic tradition, and I hope to pursue a graduate degree in Eastern Christian Studies. I study world religions because I love it and I always want to know more about other religions/worldviews.
For me this particular class on religious violence deals with a very real and widespread problem in the world that touches every religious tradition and really the whole global community. Through the class I'd like to learn how to understand the roots of this violence and to build peace in my small (or larger) way. But coming from a religious tradition, I also ask myself if religion is the problem in all this, and if at the root of all religion there will necessarily be violence. Are we the problem?

Our class has already addressed most of these problems on multiple occasions. The broad conclusions I've drawn from these discussions are that no, religion is not the only problem. Many outside contribute to religious violence as well. We've also discussed the factors inherent to religion that do feed and support this violence-- religion deals with life and death and moral code, posits a view of the cosmos that often includes an image of cosmic war, and promotes the formation of an in-group and out-group.

In the examples of religious violence that we have examined so far, most of the religious groups involved have been "fringe" groups that did not have the support of the majority of the religion or the religion's main authority. It is still important to note that these religions "gave birth" to these movements, but I'm always curious what the rest of the religious group has to say about this religious violence, and whether religion always promotes the formation of out-groups that so easily become enemies on a cosmic scale.

That's where this blog passage comes in. It comes from a popular Orthodox Christian blog (http://fatherstephen.wordpress.com/) and addresses the nature of the mind and heart in Orthodox theology. I was interested by the description of "the mind":

In order to be right about anything, the mind has the need to find someone or something that is wrong. In a sense, the mind is always looking for an enemy (the person who is “wrong”), since without an enemy, the mind is not quite sure of its own identity. When it has an enemy, it is able to be more confident about itself. Since the mind also continually seeks for certainty, which is a by-product of the desire to be right, the process of finding and defining enemies is an ongoing struggle for survival. Declaring enemies is, for the mind, not an unfortunate character flaw, but an essential and necessary task.
Unfortunately, being right is not what people really need, even though a great deal of their lives may be taken up in its pursuit. Defense of the ego is almost always a matter of trying to be right. Interestingly enough, Jesus never once suggested to His disciples that they be right. What He did demand is that they be righteous. In listening to His words we find that we spend almost all our energy in the wrong direction, since we generally pursue being right with every ounce of our being, but leave being good to the weak and the naive.
People fight wars, commit genocide, and deprive others of basic human civil liberties, all in the name of being right. There is little doubt that if a further nuclear war ever takes place, it will be because the person pushing the button believes himself to be right. About something.
Religion, at the level of the mind, can be a terrible thing, causing wanton destruction to individuals, families, and even entire nations, all in the cause of being right. Almost every religious system can, and in most cases, has operated solely at this level at some point in its history. This is the level of religious awareness that can cause the servants of the King of Peace to wage war on those who think thoughts different from their own; it bestows on those who have been commanded to forgive their enemies the right to annihilate their foes. ---Archimandrite Meletios Webber

 This mindset of us-them, right-wrong is a natural human way of seeing things. That doesn't mean that it's ok. In this particular article, Fr. Meletios continues by advocating for a religion of "the heart" which is characterized by a search for similarity rather than difference, that tries hard not to judge others, and is ego-less. Whether or not many practitioners or even leaders follow this sort of religion is another story, but I'm glad this kind of discourse exists.
From my limited knowledge, I think that Buddhism (or at least the Tibetan Buddhists that I am more familiar with) has a similar discourse. The elimination of the ego-self is an important part of Buddhist practice, and part and parcel with this is understanding the interdependence and unity of the world. I find that most religions have this sort of discourse which serves to counter in-group/out-group formation. Whether or not this is the dominant discourse seems to vary by religion and time period. But in any case, this discourse can have a positive role that could inhibit some of religion's violent tendencies. I think it is an attitude to be promoted among religious groups.