The Samoan government has decided to include compulsory teaching of Christianity in its new education curriculum. While the news report is brief, if it is true and the education is compulsory then the policy violates both the Samoan constitution and Samoa's obligations under the International Covenant on Civil and Political Rights.
Freedom of religion is guaranteed by the Samoan constitution. Furthermore, the constitution makes specific provisions for religious education, stating that
No person attending any educational institution shall be required to receive religious instruction or take part in any religious ceremony or attend religious worship, if that instruction, ceremony or worship relates to a religion other than his own.Compulsory religious instruction is a prima facie violation of that ban.
It also violates Article 18 of the ICCPR, which affirms the freedom of thought, conscience and religion, including the freedom to "have or to adopt a religion or belief of his choice, and freedom, either individually or in community with others and in public or private, to manifest his religion or belief in worship, observance, practice and teaching." The Convention's monitoring body, the Human Rights Committee, has in the past held that compulsory religious education violates those provisions:
The Committee is of the view that article 18.4 permits public school instruction in subjects such as the general history of religions and ethics if it is given in a neutral and objective way. The liberty of parents or legal guardians to ensure that their children receive a religious and moral education in conformity with their own convictions, set forth in article 18.4, is related to the guarantees of the freedom to teach a religion or belief stated in article 18.1. The Committee notes that public education that includes instruction in a particular religion or belief is inconsistent with article 18.4 unless provision is made for non-discriminatory exemptions or alternatives that would accommodate the wishes of parents and guardians.(Emphasis added)
Samoa is not a party to the Optional Protocol to the ICCPR, so its not legally binding on them. But if the policy is pursued, then it is likely to result in an adverse report from the HRC (and likely from the US State Department's annual reports on religious freedom). More importantly, given the similarity of the constitutional provision to that in the ICCPR, any competent judge considering a legal challenge would pay heed to the HRC's views - which means that unless it includes strong exemptions, the Samoan government's attempt to religiously indoctrinate its future citizens should not survive a legal challenge.