Shorter Catechism Q. 52. What are the reasons annexed to the second commandment? A. The reasons annexed to the second commandment are, God’s sovereignty over us, his propriety in us, and the zeal he hath to his own worship.
Commentary: God doesn’t merely tell us what to do, he also tells why we should do it. The second commandment includes some of those reasons, three of them to be exact. First, we are to be obey because of “God’s sovereignty over us.” If the King of England attempted to require us to pay taxes to England, we would rightly dismiss it because he has no authority over us. We don’t have to obey him because he doesn’t have sovereignty over us. But by the same taken, we ought to obey God because he is the Lord (Ex. 20:5), and thus the one who has sovereignty over us.
Second, we are to obey because of God’s “propriety in us.” Although God is God of all, he is our God redemptively, and lovingly. He has purchased us with his own blood (Acts 20:28), so that he belongs to us and we belong to him. A pastor’s child should honor his pastor because he is the pastor but also because he is his father. Christians should obey God because he is God but also because he is “our God (Ex. 20:5).”
Third, we are to obey because of “the zeal he hath to his own worship.” God is our God and he is zealous to protect that loving relationship. He will not stand idly by if we go after other gods, which is what we end up doing when we worship idols. He will punish those who hate him and love those who love him and keep his commandments. We, therefore, should obey God because we want to be blessed and not cursed (see WCF 19.6).