From Knowing Jesus by James Alison (quoted by The Girardian Lectionary):
We ended with the presence of the universal victim as the foundation for a new unity of humanity. I think therefore that one of the first questions we can ask ourselves about whether or not we know Jesus is: to what extent are we caught up in a sectarian frame of mind? To what extent are our responses tribal? ...
So, for instance, Catholics may easily talk of Protestants, or Muslims, as though the Catholic Church were superior to these other groups. Thus, belonging to the Catholic Church makes of one a superior sort of person: after all one knows the truths of the faith, and belongs to the true Church. This attitude is not uncommon, and it gives a sort of feeling of combative brotherhood with other fellow Catholics, a strengthened sense of belonging as one faces up to a world run by a hideous army of Protestants, pagans, Masons and what-have-you. In some countries the word 'Jew' would traditionally be part of this list of others. Well, I hope that gives it away. The unity that is created in this way -- even the laughing emotional bonding that seems to have no practical consequences, is created at the expense of a victim or victims, at the expense of an exclusion. That is to say, it is a unity that is derived over-against some other. And that is to betray the very deepest truth of the Catholic faith, the universal faith, which by its very nature, has no over-against. The unity which is given by and in the risen victim is purely given. It is indicative of no superiority at all over anyone else. Anyone who genuinely knows the crucified and risen victim can never again belong wholeheartedly to any other social, or cultural, or religious group. He or she will always belong critically to all other groups, because all other groups derive their unity over-against someone or some other group.
The only unity to which he or she cannot escape belonging is the new unity of humanity that the Holy Spirit creates out of the risen victim, the unity which subverts all other unities. And this new unity, given us in the Catholic Church is not yet a realized unity, as must be apparent. The Church does not teach that it is the kingdom of heaven, which is the realization of the unity in the new Israel, but that it is the universal sacrament of that kingdom. That is to say that it is the efficacious sign of a reality that has been realized only in embryo. As such, it is radically subversive of all other forms of belonging, all other ways of constructing unity. But it is so as a gift from God.
So, knowing Jesus implies, of necessity, a gradual setting free from any tribal sense of belonging, and the difficult passage into a sense of belonging that is purely given. Its only security is the gratuity of the giver, and that means a belonging in a group that has no 'abiding city,' that unlike the fox, has no hole, and unlike the bird, has no nest. You can see, I think, why it is particularly sad when Catholics turn belonging to the Church into a sectarian belonging, into a definable cultural group with a clearly marked inside and outside, and firm ideas as to who belongs outside. Of such people it can be said that they do not go in to the kingdom of heaven, and throw away the key so that others may not enter. By their very sectarian insistence on the unique truth of Catholicism, these people cut themselves off from access to the truth which they think is theirs, but which is only true when it is received as given.