In this paragraph,
        Prof. Loy is introducing his discussion of Article IV of the
        Augsburg Confession:
This fourth article
          of our Confession sets forth in words of admirable simplicity
          the doctrine of the Gospel which lay at the foundation of the
          whole glorious work of the Reformation, and which Luther
          rightly pronounced the article of a standing or a falling
          Church, meaning that this truth of the sinner’s
            justification by faith is the final test of the Christian
            Church, the departure from which would indicate its fall
            from grace and from Christ and thus manifest its apostasy
            from the truth which our Lord revealed and to which He came
            as the King of Zion to bear witness. Our teachers have
            accordingly always insisted upon this as the criterion of
            evangelical fidelity, and refused fellowship with any Church
            or party that denied, or even ignored, the fundamental
            import of this precious truth. How could they do
          otherwise, seeing that this doctrine involves the whole
          counsel of God for the salvation of all men, whom sin has
          brought under condemnation and for whom no salvation is
          possible save through the redemption which is in Christ Jesus.
          The entire cause of Christianity depends on the maintenance of
          this article in its evangelical purity.
From From Loy,
        Matthias. The Augsburg confession: An Introduction To Its
          Study And An Exposition Of Its Contents Columbus, Ohio:
        Lutheran Book Concern, 1908.



