We should not and cannot pass judgment on the Holy Spirit’s presence, operations, and gifts merely on the basis of our feeling, how and when we perceive it in our hearts. On the contrary, because the Holy Spirit’s activity often is hidden, and happens under cover of great weakness, we should be certain, because of and on the basis of his promise, that the Word which is heard and preached is an office and work of the Holy Spirit, whereby he assuredly is potent and active in our hearts (II Cor. 2:14ff.). (FC SD II, 56)
In short, enthusiasm clings to Adam and his descendants from the beginning to the end of the world. It is a poison implanted and inoculated in man by the old dragon, and it is the source, strength, and power of all heresy, including that of the papacy and Mohammedanism. Accordingly, we should and must constantly maintain that God will not deal with us except through the external Word and sacrament. Whatever is attributed to the Spirit apart from such Word and sacrament is of the devil. (SA III, viii, 9-10)
These helpful quotes are to be shared with those who look to the Spirit’s work outside of Word and Sacrament. Look for God where is says he will be, and you will find the only God that matters.