Whatever deeds we do as Christians we do as a result of His grace working in us. Because of the gracious character of these works, we have nothing of which to boast in ourselves.
Often the biblical doctrine of justification by faith alone is misunderstood to mean that good works have nothing to do with the Christian life. On the contrary, they have everything to do with the Christian life, as they are essential to our sanctification. The doctrine of justification by faith alone teaches that our works contribute nothing to our justification. Our justification rests squarely on the works of Christ alone. But we can still say that though we are justified by faith alone, our rewards in heaven are distributed according to our works. This “according to” does not mean that our works merit a reward. They do not. Our best works remain tainted with sin to such a degree that Augustine called them “splendid vices.” Augustine also taught that when God rewards our works in heaven, this is a reward grace and is, as it were, God’s crowning His own work.
Since our election is unto conformity to Christ and unto good works, we see the love of God working in our redemption from beginning to end, from election to the divine initiative by which we are brought to Christ, to the end goal of our glorification… The author of Hebrews declared that God is a rewarder of those who diligently seek Him. Yet, it is only the believer who diligently seeks God. Paul taught that by nature no one seeks after God (Rom. 3:11). The seeking of God begins at conversion; it does not end there. It is the regenerate person who seeks God and makes seeking after God the main business of his or her life.
~Adapted from Chapter Seven of God’s Love: How The Infinite God Cares For His Children[kindle edition] by R.C. Sproul.