What qualification for public office is explicitly forbidden by the Constitution?

The Constitution explicitly forbids the use of religious tests as a qualification for public office. This prohibition is established in Article VI, Clause 3, which states that no religious test shall ever be required as a qualification to any office or public trust under the United States. This provision reflects the Founding Fathers' commitment to religious freedom and the principle that government should not favor or discriminate against individuals based on their religious beliefs. By ensuring that no one can be disqualified from holding office because of their religion, the Constitution promotes the idea of a secular government that respects diverse beliefs and upholds the separation of church and state.