Answer: The part of the First Amendment that prohibits the government from establishing an official religion is known as the establishment clause. This clause is a cornerstone of the constitutional principle of separation of church and state and ensures that the government is not allowed to favor or promote any particular religion over others. The other clauses in the First Amendment include the free exercise clause, which guarantees the right to practice religion freely, and the freedom of speech, press, assembly, and petition clauses. These clauses are all essential components of the First Amendment and help to protect individual liberties and ensure a free and open society.