I just finished an excellent book by Terry Virgo of New Frontiers Ministries titled, God's Lavish Grace. Terry is by far the best teacher I have ever heard/read regarding the topics of grace and justification.
His word picture of the law as a perfect yet overbearing, impotent husband makes it so clear how the only way for us out of that marriage is for us to die and then, once dead, we are free to marry Christ who gives us the ability to now bear fruit! But it doesn't stop there because we now understand that we do not please our new lover by meeting the expectations of our old husband.
He then has an excellent word picture using movement between time zones to help us understand how we are now fully righteous and what our attitude and behaviour should be toward that.
Finally, he has a simple but tremendous chapter about giving in which he shows us from 2 cor 8 that the basis for financial giving is the grace we receive from God.