There is only one article and one rule of theology, and this is true faith or trust in Christ

There is only one article and one rule of theology, and this is true faith or trust in Christ. Whoever doesn’t hold this article and this rule is no theologian. All other articles flow into and out of this one; without it the others are meaningless. The devil has tried from the very beginning to deride this article and to put his own wisdom in its place. However, this article has a good savor for all who are afflicted, downcast, troubled, and tempted, and these are the ones who understand the gospel. – Martin Luther 1532