Is the authority the Bible as explained by Luther?
Or by Calvin?
Or by Zwingli?
Or by Arminius?
Or by George Fox?
Or by Mary Baker Eddy?
Or should the Christian pick and choose what he feels true from this smorgasbord??
Since you included Mary Baker Eddy I can’t take this too seriously. If you genuinely want to understand, I suggest you study the links I suggested. The answers aren’t hard to find. I’ve got the flu and don’t want to spend time and energy trying to write something that is readily available elsewhere.