“I have been crucified with Christ. It is no longer I who live, but Christ who lives in me. And the life I now live in the flesh I live by faith in the Son of God, who loved me and gave himself for me.” Galatians 2:20 ESV
For Paul, 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…
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 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 [justification], in which the believer finds peace and joy and comfort and gratitude.
~ Jerry Bridges and Bob Bevington in The Bookends of the Christian Life, page 29.