We cannot yield or surrender anything of what we believe about the chief article...

Of this article [The chief article] nothing can be yielded or surrendered, even though heaven and earth and everything else falls.  "For there is no other name under heaven given among men by which we must be saved" (Act 4:12). "And with His stripes we are healed" (Isaiah 53:5).  Upon this article everything that we teach and practice depends, in opposition to the pope, the devil, and the whole world.  Therefore, we must be certain and not doubt this doctrine.  Otherwise, all is lost, and the pope, the devil, and all adversaries win the victory and the right over us.
~BOC, SA, II, I, 5