Justification by grace alone is the hinge on which the Protestant Reformation turns. Calvin’s favorite word for justification was “acceptance.” To Luther first, and then to Calvin, the peril in the Christian religion is that believers might imagine they can achieve an acceptable status with God.
“No,” said the Reformers. “Never. You are acceptable to God only on God's terms, not yours. And your acceptance depends wholly on the vicarious achievement of another—Jesus Christ. Your justification is by grace alone and is received through faith alone. Your newness of life is by grace, and so is your final glory. All your goodness is derivative; all your splendor is reflected light. For the whole run of your life—beginning, growth, flowering—you are at every point dependent on the gracious energy of God.”
Suppose we define grace as undeserved favor. What is the profile of grace?
1. Grace Redeems
Grace aims to redeem. There are of course common graces (rain on the just and unjust alike), but God’s grace confers not only general goods, but also and especially redemption of guilty sinners. Hence grace words are used particularly with such themes as salvation, justification, election, adoption, and reconciliation. God’s grace comes to sinners, to people who have thought and spoken and acted badly—or who have failed to think and speak and act righteously. The healthy have no need of a physician's good graces. It is sinners who need grace. And it is the misery of sinners that needs mercy.
2. Grace Overcomes Sin
God’s grace powerfully redeems; i.e., grace overcomes sin. It doesn't just excuse or tolerate it. Certainly it doesn't just prettify or embellish it. Grace is not just a grace note. It is a power that is aimed at wholesale remaking of people who are guilty and stubborn. Grace works on people who are lousy patients—people who resist and resent any graceful great physician. Grace is tough love that remakes people sometimes in spite of themselves.
Grace is now the dominant power, says Paul in Rom 5:21.
3. Grace Is Free
Grace is free but not cheap. As Heb. 10:29 and other scriptures show, grace is always held out to us in wounded hands. It hurts even us to grace another. How much more does it hurt the son of God who is gracing a whole world. Grace is graciously given, but it is expensive, and it always comes to us with blood on it.
4. Grace is Lavish
Grace is lavish, profuse, and uncalculating. Its source is not a pipe but a fountain that sprays in every direction. Jesus Christ comes with a fullness, a pleroma of grace (John 1:16). That's why there is an unrestrictedness to grace: it does not color just Israel, nor just Lutherans, say, nor even just believers. Grace is common for everyone and special for all kinds of people. Indeed, we may harbor private hopes that grace extends even further than that. There is something peculiarly gracious about the universalism of an Origen or a Clement of Alexandria, even if we reluctantly conclude that we cannot share their confidence in the matter.
Grace is lavish, profuse. And it is uncalculating. In Luke 15, a shepherd leaves 99 sheep to go out after 1—maybe not wise, but gracious. In Matthew 20, an employer pays latecomers just as much as those who have labored from the crack of dawn through the midday heat. Not good labor policy, but lavishly gracious. In Luke 15, a waiting father stands by a fence peering down the road that winds in from the far country, straining his eyes toward the familiar gait of his prodigal son. The son has a memorized confession he wants to make, but the father is heedless of that. All he wants is a celebration. Amazing grace. Not a trickle, but a flood tide.
5. Grace is Surprising
Accordingly, grace is surprising, unexpected. There is a sudden loveliness about grace, a peculiar beauty. The Prodigal son expects a lecture and gets a hug. Peter expects a special rebuke for his faithlessness in denying Jesus: what he gets is a special heavenly announcement of the resurrection, addressed just to him. In Mark 16 a young man at the grave of Jesus addresses three frightened women who are first at the tomb: "Don't be alarmed," he said. "He is not here. He has risen. Go, tell his disciples and Peter."
Why Peter, especially? Because he's guilty and feeling guilty. Because he thinks he's no longer a disciple. "Go, tell his disciples and Peter." Special grace for special guilt.
The grace we celebrate as Christians and as children of the Reformation is free, undeserved favor which is lavish, uncalculating, and surprising in its loveliness. We see it in the figure of the waiting father in our Lord's parable from Luke 15. One of his sons left home; one froze the home. It's impossible to say or to think who had been further from his father.
But it is also impossible to say or to think what amazing grace this is that runs out to meet and embrace us while we are yet sinners, while we are yet at a distance, and in that meeting and in that embrace to welcome us home.