Freedom of a Christian

Martin Luther's writing on the Freedom of a Christian was interesting. Toward the beginning he said "A Christian man is the most free lord of all, and subject to none, a Christian man is the most dutiful servant of all, and subject to every one." This totally confused me, but as I read on I understood that he was talking about the inside soul and the outside human of a person. That to him being a Christian was something that is on your inside, your soul and that the outside was basically your shell while on earth. He also said that things that can harm the body do not harm the soul and that even though the body dresses and does Christian things does not mean the soul is Christian. The point Martin was making by all this was that Christianity for a person was based on the faith. That faith resided in the soul alone and no where else. I thought this was a interesting point that Martin Luther made about Christianity.