Almost all international conventions grant the right to freedom of religious expression, assembly and association: Art. 9 para. 2 ECHR justifies a restriction of freedom of religion if prescribed by law or necessary in the interest of public safety. In some cases, this right includes the right to mission and to present one’s own faith as worthier than other faiths. This was the case in the sentence no. 188 by the Italian Constitutional Court (18.07.1975). This paper will investigate from the perspective of international law where the right to mission has to be restricted. Taking into account cases such as Kokkinakis vs. Greece, it will ask how national ecclesiastical and international law should deal with religious organizations such as the Mission to Amish People or Jews for Jesus, both of which have the purpose of converting Amish people or Jews to evangelical Christianity.