In the south you can/do lose your job house and friends if you come out of the closet as a non-believer. In Tennessee and some other states you can't run for elected office unless you pass the religious test.
Article IX, Sec. 2, of the Tennessee constitution (engagingly titled "No Atheist shall hold a civil office"): "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."