Religious education may be the means whereby religion gains influence in political matters or over society at large. It usually involves segregation according to denomination, serves to reinforce existing prejudices, and may ultimately lead to discrimination, conflict and even war.
Denominational education exists world wide and is particularly important for Islam, Christianity and Judaism. It may be the main source of education and therefore be equated with prestige, making many converts for this reason and thus being a foundation for nationalism and other political policies. It may have an influence on the law. Religious teaching in schools is a matter of controversy in Western industrialized countries, especially where immigrant populations prefer religious teaching in their own traditions, rather than those of the host country.
In the case of Christianity, for example, most new catechisms and religious instruction books have no section on the basic beliefs of other religions. A vast majority of Christians do not gain insight in the spirituality and ethics of others.