The Ten Commandments provide lines for our relationships – the first four deal with vertical lines (with God) and the last six deal with horizontal lines (with others). The love that God has shed abroad in our hearts we are to show to others.
Mankind is the mirror of God. So the way we bring glory to God is by valuing the image of God in others. We love what he loves. Murder, on the other hand, is at root the attempt to play God and it begins with the small seeds of bitterness and hatred.
This is the first commandment concerning our horizontal relationships. Lest we think it only applies to kids, we are all children. Therefore this command to honor our parents has application for all people.