One of man's primary needs is the need to belong to a certain group. It goes with his desire to be accepted as a person. However just like any process of communication, it is always a two-way process meaning he needs to be accepted by the other members of that group and at the same time, he needs to accept the whole package of that group so as to be considered as in the group.
Different stages are involved in this process of integrating oneself into the group. At a certain stage, personal values need to be aligned with that of the group. Maybe there could be instances that he needs to sacrifice for the sake of the group. Citing a concrete example of this, if the group is actively participating and responding to the social needs of the times like poverty, social discrimination, racial issues, etc. then he has to convince himself that he values these issues personally so that he can extend a genuine participation to the cause of the group.
Oneself vs. themselves......man vs. community....him vs. them....sometimes a conflict between any of these groups but somehow, the tides can be turned against a conflicting situation and finally emerging as victorious at the end. Hence the best way to belong to a particular group is by initially checking what are the values this group has and compare them with one's own values.
