The Rise of Religious Nationalism - Conversion, Proselytism, and the UN
Marshall, Paul, The World and I
The UN Declaration on the Elimination of All Forms of Intolerance and of Discrimination Based on Religion or Belief, 1981 doesn't assert a right to change a religion but only to adopt a religion. However, as Natan Lerner, perhaps the leading authority on the matter, observes, "There is no doubt ... that the final text recognizes the right to change one's religion or beliefs, to abandon a religion and to adopt a different one."
A new Article 8 was added precisely to reinforce this point. This article says "nothing in the present Declaration shall be construed as restricting or derogating from any right defined in the Universal Declaration of Human Rights." The 1948 Universal Declaration in Article 18 states in turn that "everyone has the right to ... change his religion or belief."
The UN Human Rights Committee further stressed this in its 1993 comment that article 18 (1) of the International Covenant on Civil and Political Rights emphasizes "the right to replace one's current religion" and says "the freedom to ... adopt a religion [is] ... protected unconditionally" and "cannot be derogated from, even in time of public emergency."
In turn, actually propagating a religion is a basic human right, asserted in the Declaration and protected by the International Covenant in Article 19, which covers freedom of expression. Freedom of religion always manifests itself through free speech, free expression, and freedom of association. The right to propagate one's religion is simply a right of free speech. …