Calvin's God-Exalting Piety

What good is John Calvin the Theologian for us Today? Well, He is more than a theologian. He shows us that theology produces piety. see the pdf for more, but enjoy this quote for now:

We are God's: let us therefore live for Him and die for Him.
We are God's: let His wisdom and will therefore rule all our actions.
We are God's: let all the parts of our life accordingly strive toward Him as our only lawful goal.
(John Calvin, Institutes, 3.7.1)