The ONLY authority is God’s Holy Spirit Word for God’s children.
Anyone following anyone/anything else is satan’s children.
Some believe they are choosing not to follow the authority of other fallible men by deciding that they alone will decide what Holy Scripture is and what it means.
Most who make this choice are at least consistent in its application. A few are not:
"A Protestant believes in no infallible authority; he is an authority unto himself, which authority he does not claim to be infallible, if he is sober and sane."