Here you see again how highly and preciously we should value Baptism, because in it we receive such an unspeakable treasure. This also proves that it cannot be ordinary, mere water. For mere water could not do such a thing. But the Word does it and, as I said above, so does the fact that God's name is included in Baptism. Where God's name is, there must also be life and salvation (Psalm 54:1). So Baptism may certainly be called a divine, blessed, fruitful and gracious water. Such power is given to Baptism by the Word that it is a washing of new birth, as St. Paul also calls it in Titus 3:5.
Martin Luther, from the Large Catechism, page 452 in Concordia ~ The Lutheran Confessions
