" The article of justification is fragile. Not in itself, of course, but in us. I know how quickly a person can forfeit the joy of the Gospel. I know in what slippery places even those stand who seem to have a good footing in the matters of faith. In the midst of the conflict when we should be consoling ourselves with the Gospel, the Law rears up and begins to rage all over our conscience. I say the Gospel is frail because we are frail. "

― Martin Luther , Commentary on Galatians