This is a great little book on justification and sanctification: The Bookends of the Christian Life. I appreciated the following paragraphs near the beginning of the book.
“For Paul (cf. Rom. 5:1 and Gal. 2:15-21), justification was not only a past event; it was also a daily, present reality. So every day of his life, by faith in Christ, Paul realized he stood righteous in the sight of God – he was counted righteous and accepted by God as righteous – because of the perfectly obedient life and death Christ provided for him. He stood solely on the rock-solid righteousness of Christ alone, which is our first bookend.
We must learn to live like the apostle Paul, looking every day outside ourselves to Christ and seeing ourselves standing before God clothed in his perfect righteousness. Every day we must re-acknowledge the fact that there’s nothing we can do to make ourselves either more acceptable to God or less acceptable. Regardless of how much we grow in our Christian lives, we’re accepted for Christ’s sake or not accepted at all. It’s this reliance on Christ alone, apart from any consideration of our good or bad deeds, that enables us to experience the daily reality of the first bookend, in which the believer finds peace and joy and comfort and gratitude.
…Because we have a natural tendency to look within ourselves for the basis of God’s approval or disapproval, we must make a conscious daily effort to look outside ourselves to the righteousness of Christ, then to stand in the present reality of our justification.”