Wherever faith is not preached and is not given primary importance, wherever we do not begin by learning how we are united with Christ and become branches in Him, all the world concentrates only on its works.  On the other hand, wherever faith alone is taught, this leads to false Christians, who boast of their faith, are baptized, and are counted among the Christians but give no evidence of fruit and strength.  This makes it difficult to preach to people.  No matter how one preaches, things go wrong; the people always hedge.  If one does not preach on faith, nothing but hypocritical works result.  But if one confines one’s preaching to faith, no works ensue.  In brief, the outcome is either works without faith or faith without works.  Therefore the sermon must address itself to those who accept and apprehend both faith and works; the others, who do not want to follow, remain behind.  Just as the devil, who is the god and lord of the world, will never become pious, so it will never be possible to make the whole world pious.  And no matter how much one says to the world, it grows defiant and does all the more in opposition.  It takes this as a provocation to be even worse.  Because these people refuse to hear and to believe, we let them go their way until they find and experience the truth, not only in eternity but also here in this temporal life.

But we preach to the little flock, who know, and reflect on, their eternal destiny, whose chief concern is to remain in this Vine, who find all their consolation in Him, and who then also give practical proof of this in their conduct.  For faith will surely manifest itself in such fruit, as Christ said earlier: “He who abides in Me bears much fruit.”

Luther’s Works, vol. 24, pp. 249-250.