Freedom of religion is one of the most important ideas in the United States Constitution. Therefore, it would make no sense whatsoever to allow any sort of religious test for people who want to hold office in the US government. We can see this stated explicitly in Article VI of the Constitution. There, it says that essentially all government officials, whether they are state officials or federal officials, just swear or affirm that they will support the Constitution. However, it is not legal for any religious test to be imposed for any office in the US government or the state governments.