The First Amendment gives us freedom of religion. Here's the text:
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the government for a redress of grievances."
It is stated in the first section ("Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof...")
Hope this helps!