I twigged to something today while listening to the very excellent Sonship series taught by Barry Henning of New City Fellowship, St. Louis.

The reason why God doesn't give us righteousness or salvation or anything else in response to our own efforts or attempts at living righteously, is that to do so would be to place God in man's debt. This in turn would make God into not-God, but a cosmic genie who exists to bend himself to man's will and to fulfill the legitimate demands placed on him by our good works. It would mean that we could manipulate God into giving us what we deserve for our efforts.

This is impossible. Instead, as Paul rapturizes in Romans 11:

Oh, the depth of the riches of the wisdom and knowledge of God!
How unsearchable his judgments,
and his paths beyond tracing out!
"Who has known the mind of the Lord?
Or who has been his counselor?"
"Who has ever given to God,
that God should repay him?"
For from him and through him and to him are all things.
To him be the glory forever! Amen. (Romans 11:33-36)

The reason that righteousness comes only as a gift, never in response to our own efforts, is not only that it is impossible for us to establish our own righteousness due to sin. It is also so that, by doing so, God ensures that all the glory will go to him. As it is rightly so. However, we are the beneficiaries of this boundless and totally free generosity, received only by faith and not by any works we have done!

It seems like a good system to me.