But not only that! The devil has armed himself with these things in order to abolish God’s word and sacraments with them. This is his line of thought: if someone arises to attack my church, sacraments, and bishops, saying that external things do not save, then God’s word and sacraments shall perish with them, for these too are external signs and his church and bishops are also human beings. If mine do not stand approved, his will stand approved even less, especially because my church, bishops, and sacraments work promptly and help now and in this life, visibly and tangibly, for I am present in them and help quickly, as soon as it is desired. Christ’s sacraments, however, work spiritually and invisibly and for the future so that his church and bishops can only be smelled, as it were, faintly and from afar, and the Holy Spirit behaves as though he were absent, permitting people to endure every misfortune and making them appear as heretics in the eyes of my church. Meanwhile, my church is not only so close that one can actually grasp it, but also my works follow very quickly; so everyone assumes that it is the true church of God. This is the advantage I have. (Luther’s Works, v.41, p.169-170)
Picture: The picture of the narthex window (updated to English) has been flipped so that you can read what was designed to be read from the outside of the church.