Since it is a known fact that the "point de depart" of "Nostra Aetate" is the recognition of diversity, pluralism, and inclusiveness in modern society in its declaration more than forty years ago, it is the aim of this paper to point out the pedagogical problems and difficulties underlying the continued and intentional segregation of children from the same or within the same society based on religious belief and faith, especially in line with the noble intention of the same document to enhance mutual relations with other non-Christian religions, especially Muslims and Jews (as well as Buddhists, Hinduists) etc. There are two ways of looking at this: from the point of view of the type of education given to children and young ones in the name of religious beliefs and from the type of social attitudes they are meant to exhibit, which cuts them off from normal interaction with other children. The conclusion of the paper will point to the type of danger associated with this kind of segregation or isolation, leading to discriminative behaviour--especially as it works against the dynamic principles of social behaviour, based on openness and the moral values of justice, love, and honesty. The paper, whose approach is interdisciplinary, also shows that religion when mishandled, could be a major instrument of social disruption, especially in a pluralist and multi-cultural society, thus working against the very purpose of writing "Nostra Aetate" by the Second Vatican Council Fathers.