For the Word, whereby we are called, is a ministration of the Spirit, that gives the Spirit, or whereby the Spirit is given, 2 Cor. 3:8, and a power of God unto salvation, Rom. 1:16. And since the Holy Ghost wishes to be efficacious through the Word, and to strengthen and give power and ability, it is God's will that we should receive the Word, believe and obey it.
Book of Concord, 1580