Question: Where does it say we have freedom of religion?
Disambiguated questions and answers: question: Where does it say we have freedom of religion in the United States?
Where does it say we have freedom of religion in the State of Palestine?
Where does it say we have freedom of religion in Canada?
Where does it say we have freedom of religion internationally?
answer: First Amendment of the United States Constitution
the Basic Law
the Canadian Charter of Rights and Freedoms
Declaration on the Elimination of All Forms of Intolerance and of Discrimination Based on Religion or Belief
Natural Questions answer: the First Amendment (from the Wikipedia article "Freedom of religion in the United States")