Under Tennessee's Constitution, "no person who denies the being of God, or a future state of rewards and punishments, shall hold any office in the civil department of this State." Thus, Atheists are apparently not allowed to hold public office in Tennessee.

It is not uncommon to require an oath of office that involved pledging to God or some higher power. The point, of course, is that governments believe that by requiring a person to swear upon something they believe to serve as a spiritual check, there will not be the ability to abuse the power of the office, since the person will fear some sort of punishment or other ramifications.

What is particularly interesting about Tennessee's version, though, is that it specifically outlines a sort of afterlife requirement for religion, rather than a bigger than thou sort of belief. It makes me wonder whether this not only violates  a preference for religion in general, but also for a Christian type of religion or the like.

In California, the oath attorneys must take involves upholding the U.S. and California Constitutions, which apparently has some religious implications as well.