“To annoy the devil, I say, we should always have this holy name of the Lord in our mouth, so that the devil may not be able to injure us as he wishes. For this purpose it also helps that we form the habit of daily commending ourselves to God, with soul and body, wife, children, servants and all the we have, against every need that may occur. That is why we have blessing and thanksgiving at meals, and other prayers for morning and evening have originated and remain in use.
A simple help appears in the children’s practice of crossing themselves when anything monstrous or terrible is seen or heard, and they exclaim “Lord God, protect us!” “Help, dear Lord Jesus!” etc. Also, if anyone meets with unexpected good fortune, however trivial, he may say “God be praised and thanked; God has bestowed this on me!” etc.
See, in this way, we might train our youth in a childlike way and playfully in the fear and honor of God. Then the First and Second Commandments might be well kept and in constant practice. Then some good might take root, spring up and bear fruit, and people may grow up whom the whole nation may desire and enjoy. In addition, this would be the true way to bring up children well as longs as they can become trained with kindness and delight.” (Martin Luther, Large Catechism I, 72-76)