We Must Be Alert

Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour.
1 PETER 5:8
We Must Be Alert
Whether someone acts arbitrarily against Christ, without Christ, or under the guise of His name, it is immaterial; it is all against Christ. Therefore we must be on the alert against the devil, who assails us either with doctrine that runs counter to Christ, as the tyrants do, or with doctrine that is devoid of Christ, as the canon laws do. And others will come with the Scriptures and give themselves the semblance of the Lord Christ; this, of course, is also against Christ. Christ alone must remain the Bridegroom; He alone is vested with authority and must be heard, as the voice from heaven declared (Matthew 17:5)..And now all those who are not Christ's own, that is, all those who are not His spokesmen, really ought to keep silence. We should be satisfied with Him. We should not wait for Moses, much less for others; for God has put His Word into His mouth. He alone is to have a voice in the chamber, for the Father entrusted this to Him; and we are to hearken to no other, be it Moses or an angel from heaven, as St. Paul says (Galatians 1:8).

From Sermons on the Gospel of John, Chapters 1-4 (Luther's Works 22:445)