Theological Ethics, Grace and Law

An ethic is theological if it begins with God, rather than humanity. Who is God, and what is his purpose for humanity, and how is that implemented in our lives. Jesus gave two love commands: to love God with all that we are, and to love our neighbors. We cannot ignore the first (or collapse it into the second), for it is the foundation of the second. God sets the example, provides the motivation, and works it out in us. He has described for us what it should look like. But what then is the role of grace? Does it negate the importance of the ethics God has given? How do the statements of grace fit in with the commands of the New Testament?