Everyone has the right to freedom of thought, conscience and religion; this right includes freedom to change his religion or belief, and freedom, either alone or in community with others and in public or private, to manifest his religion or belief in teaching, practice, worship and observance.
The Universal Declaration of Human Rights, Article 18. Emphasis mine. Those who want to confine freedom of religion in America to freedom of worship — and I have heard from a number of them lately — might want to reflect on their dissent from this document.
Further commentary from Lord Alton of Liverpool here.