God rules His universe by law. Nature itself operates under His providential government. The so-called laws of nature merely describe God's normal way of ordering His universe. These "laws" are expressions of His sovereign will.
God is not accountable to any laws outside of Himself. There are no independent, cosmic rules that God is obligated to obey. Rather, God is a law unto Himself. This simply means that God acts according to His own moral character. His own character is not only morally perfect, it is the ultimate standard of perfection. His actions are perfect because His nature is perfect, and He always acts according to His nature. God is therefore never arbitrary, whimsical, or capricious. He always does what is right.
As God's creatures, we are also required to do what is right. God demands that we live according to His moral law, which He has revealed to us in the Bible. God's law is the ultimate standard of righteousness and the supreme norm for judging right and wrong. As our sovereign, God has the authority to impose obligations on us, to command our obedience, and to bind our conscience. He also has the power and right to punish disobedience when we violate His law. (Sin may be defined as disobedience to God's law.)
Some laws in the Bible are directly based on the character of God. These laws reflect the permanent, transcultural elements of relationships, both divine and human. Other laws were intended for temporary conditions of society. This means that some laws are absolute and eternal, while others may be annulled by God for historical reasons, such as the dietary and ceremonial laws of Israel. Only God Himself may set aside such laws. Human beings never have the authority to set aside God's law.
We are not autonomous. That is, we may not live according to our own law. The moral condition of humankind is that of heteronomy: we live under the law of another. The specific form of heteronomy under which we live is theonomy, or the law of God.