I ran across this great quote from the Large Catechism on the Blog of Saint Mark. Check it out!
This, now, I say should be the first and most important consideration that urges us to keep this commandment. Because of this, even if we had no father and mother, we should wish that God would set up wood and stone before us, so that we might call them father and mother. Since He has given us living parents, how much more should we rejoice to show them honor and obedience? For we know it is so highly pleasing to the Divine Majesty and to all angels, and it harasses all devils. Besides, this is the highest work we can do, after the grand divine worship included in the previous commandments. Giving to the poor and every other good work toward our neighbor is not equal to this. For God has assigned parenthood the highest place. Yes, He has set it up in His own place upon the earth. God’s will and pleasure ought to be enough reason and incentive for us to do what we can with good will and pleasure.
Besides this, it is our duty before the world to be grateful for benefits and every good that we have from our parents. But here again the devil rules in the world [Ephesians 6:12], so that the children forget their parents. We all forget God, and no one considers how God nourishes, protects, and defends us, and how He bestows so much good on body and soul [Psalm 23]. This is especially true when an evil time comes. We grow angry and grumble with impatience, and all the good that we have received throughout our life is wiped out ‹of our memory [Psalm 78:17–31]›. We act the same way toward our parents, and there is no child that understands and considers ‹what the parents have endured while nourishing and fostering him›, unless the Holy Spirit grants him this grace.
God knows very well this perverseness of the world; therefore, He admonishes and urges by commandments that everyone consider what his parents have done for him. Each child will discover that he has from them a body and life. He has been fed and reared when otherwise he would have perished a hundred times in his own filth. Therefore, this is a true and good saying of old and wise people: “To God, to parents, and to teachers we can never offer enough thanks and compensation.” The person who thinks about and considers this will give all honor to his parents without force and bear them up on his hands as those through whom God has done him all good [Psalm 91:12].
Over and above all this, another great reason that should move us more to obey this commandment is that God attaches to it a temporal promise: “That your days may be long in the land that the LORD your God is giving you” [Exodus 20:12].
From this you can see for yourself how serious God is about this commandment. He not only declares that it is well pleasing to Him and that He has joy and delight in it, but He also declares that it shall prosper us and promote our highest good, so that we may have a pleasant and agreeable life, furnished with every good thing. Therefore, St. Paul also greatly emphasizes the same promise and rejoices in it when he says that this is the first commandment with a promise, “that it may go well with you and that you may live long in the land” (Ephesians 6:2–3). Although the rest of the commandments have promises in them, none is so plainly and clearly stated.
–Martin Luther, The Large Catechism, Part I: The Ten Commandments, paragraphs 125-133