This is the fundamental commandment, the one that comes before all the others and lays the foundation for them. Before we learn anything else about what God demands, we need to know who he is, and who we are in relationship to him. “Now get this straight,” God is saying, “I am the one and only God. And since I am the only God, I refuse to share my worship with anyone or anything else.” God will not share the stage with any other performers. He refuses to have any colleagues. He will not even acknowledge that he has any genuine rivals. God does not simply lay claim to one part of our life and worship; he demands that we dedicate all we are and all we have to his service and praise. Thus the Ten Commandments begin by asserting the great theological principle of soli Deo gloria: glory to God alone.
—Philip Graham Ryken, Written in Stone: The Ten Commandments and Today’s Moral Crisis (Wheaton, IL: Crossway Books, 2003), 57–58.