I've heard it more than once, and wonder it all the time: "Okay, salvation by grace through faith in Christ. Gotcha. But what about living out the Gospel?" Plenty of others wonder, too.
Because of the nature of Christ's work for us
, its fullness and completeness apart from any of our work or merit, a description of the lifestyle of an orthodox Christian is extremely hard to characterize. How then do we live? As Gerhard Forde points out in On Being a Theologian of the Cross
It is quite impossible to write "the" or even "a" theology of the cross. The attempt to do so would no doubt be just another attempt to give a final propositional answer to Jesus' cry from the cross, "My God, My God, why have you forsaken me?" We can't answer Jesus' question. We can only die with him and await God's answer in him. To claim such an answer would simply be to leave the actual cross behind for the sake of the theology in our books. It would be just another theology about the cross, not a theology of the cross. Basically, all theologies about the cross turn out to be theologies of glory.
The difficulty here is that the cross is the theo-logy, the logos of God; the word of the cross is the attack. It doesn't coin itself in ready theological propositions that we can appropriate and still go on pretty much as usual. The word of the cross kills and makes alive. It crucifies the old being in anticipation of the resurrection of the new. "The cross alone is our theology," Luther could say. And those oft-quote words are to be taken literally. But we cannot fail to notice what an odd claim it is. How can the cross be a theology? The cross is an event. Theology is reflection on and explanation of the event. Theology is about the event, is it not? However, that is what makes writing some definitive theology of the cross impossible. At best all such theology can do is to clear the way for the proclamation of the cross, to drive us actually to preach the word of the cross as that folly that destroys the wisdom of the wise.
All of the work required to make us Christians is done by Father, Son, and Holy Spirit. But our lives go on minute by minute. What are we left to do?
Then said they unto him, What shall we do, that we might work the works of God? Jesus answered and said unto them, This is the work of God, that ye believe on him whom he hath sent.
- John 6:28-29
We are left, by grace, to walk in faith. Believing in Christ is the work of God. And what has Christ done for us? He has finished our work, which is why he tells us only to believe that he has done it.
That work Christ performed in his life, death, burial, and resurrection is double edged: It is the ultimate attack on sin, and the ultimate creative work of new life.
"The love of God does not first discover but creates
what is pleasing to it," writes Martin Luther. Delivered to us
in Word and Sacrament, that work of Christ is all-sufficient and without fault. This is exactly what Luther is getting at when he writes his introduction to the Apostle's Creed in the Large Catechism:
Thus far we have heard the first part of Christian doctrine, in which we have seen all that God wishes us to do or to leave undone. Now, there properly follows the Creed, which sets forth to us everything that we must expect and receive from God, and, to state it quite briefly, teaches us to know Him fully. And this is intended to help us do that which according to the Ten Commandments we ought to do. For they are set so high that all human ability is far too feeble and weak to [attain to or] keep them. Therefore it is as necessary to learn this part as the former in order that we may know how to attain thereto, whence and whereby to obtain such power. For if we could by our own powers keep the Ten Commandments as they are to be kept, we would need nothing further, neither the Creed nor the Lord's Prayer.
That power is obtained by belief in Christ. We "live out" our faith by believing
that Christ's work, put into us, is creating in us a clean heart, renewing within us a right spirit. We live out our faith by believing in the grace of God, for us, in all times: past, present, and future.
What shall I render to the Lord for all His benefits toward me? I shall lift up the cup of salvation, and call upon the name of the Lord. I shall pay my vows to the Lord.
- Psalm 116:12-14
John Piper likes to say that this kind of "payback" consists of God filling our cups of salvation so that we may continually drink more deeply.
There is no formula here, no fad theology or twelve-step method, only Fact: The Fact of Christ Jesus and the utter objectivity of his work on our behalf.
Believe in the utter freedom we have as Christians, saved by grace. We are freed to say with Christ (and really believe) that "Blessed are the poor in spirit, blessed are the mourners, blessed are the meek..." We are freed to run the race that Christ has marked out for us, because Christ himself gives us every drop of strength we need. Believe.
I'm not saying that we will never sin again, or that life is rosey when we believe. But if believing is the very work of God. then every sin must be an act of unbelief, even if it's only momentary. Life is not easy when we believe--Christ told us it would not be--but his work in us is perseverance, life, and peace.
When a man believes that in himself, Christ has accomplished all good work and continues to accomplish good work, how does he live? How does he love his wife and child, when he believes completely that Christ has accomplished in him perfect love? How does he look at his career and his finances when he believes that Christ has accomplished all perseverance and humility? How does he deal with his failures, when he believes that in him, Christ has given endless grace?
"I believe, help thou my unbelief," thus becomes the cry of every Christian. Life no longer is a "To Do" list, but a "Done" list. Our challenge is believing it.
Rich Mullins, in the refrain to his driving arrangement of the Apostle's Creed, sings:
I believe what I believe
Is what makes me what I am
I did not make it,
No it is making me
It is the very truth of God
and not the invention of any man.
I believe it, I believe it.