69 Therefore I advise and urge, as I have before, that by means of warning and threat, restraint and punishment, children be trained in due time to shun falsehood and especially to avoid calling upon God’s name in its support. …70 On the other hand, children should be constantly urged and encouraged to honor God’s name and keep it constantly upon their lips in all circumstances and experiences, for true honor to God’s name consists of looking to it for all consolation and therefore calling upon it. Thus, as we have heard above, the heart by faith first gives God the honor due him and then the lips do so by confession….
73 For this purpose it also helps to form the habit of commending ourselves each day to God — our soul and body, wife, children, servants, and all that we have — for his protection against every conceivable need. Thus has originated and continued among us the custom of saying grace and returning thanks at meals and saying other prayers for both morning and evening. 74 From the same source came the custom of children who cross themselves when they see or hear anything monstrous or fearful and exclaim, “Lord God, save us!” “Help, dear Lord Christ!” etc. Thus, too, if anyone meets with unexpected good fortune, however trivial, he may say, “God be praised and thanked!” “This God has bestowed upon me!” etc. Children used to be trained to fast and pray to St. Nicholas and other saints, but the other practices would be more pleasing and acceptable to God than any monastic life and Carthusian holiness. (Large Catechism -Tappert, p. 374-375).