The question comes (paraphrasing):

Since Scripture says, “believe,” (e.g. Acts 16:31) it seems that we are commanded to believe. If the command to believe is an imperative and an imperative is “law,” and if the answer to the command “believe” is faith, then faith must be a type of obedience. If so, aren’t faith and obedience essentially the same thing?

Ursinus wrote:

The chief and most important parts of the first principles of the doctrine of the church, as appears from the passage just quoted from the Epistle to the Hebrews, are repentance and faith in Christ, which we may regard as synonymous with the law and gospel. Hence, the catechism in its primary and most general sense, may be divided as the doctrine of the church, into the law and gospel.

First we must get our categories right. According to Ursinus repentance is a corollary to “law” or “do this and live” and faith is a corollary to “gospel,” or “Christ has fulfilled the law for you who believe.” According to Ursinus, there are ways in which the law and the gospel agree and ways in which they are opposed to each other:

The gospel and the law agree in this, that they are both from God, and that there is something revealed in each concerning the nature, will, and works of God. There is, however, a very great difference between them….

Both the command to “do and live” and the command “believe” reveal the will of God. They are both imperatives. What this means is that not every biblical imperative is “law.” It is true that, in the controversy with the covenantal moralists (Federal Vision, NPP, Norman Shepherd) I have often said that the law says “do” and the gospel says “done.” Strictly speaking that it is true but it is also true that one must use some language to communicate to another that, in view of the demands of the law, one must satisfy the law oneself or by another. The announcement that another, a Mediator, has satisfied the demands of the law is in the indicative mood. The call to believe, to receive, to accept for oneself, to rest in the truth of that announcement is in the imperative.

There is a false premise in the initial question. If all imperatives are “law” then the imperative “believe” is a law and the act of faith must be “obedience.” The false premise is this: if imperative, then law. This doesn’t follow. Yes, both the law and the gospel have conditions and imperatives but they are not the same conditions nor are they the same imperatives. The gospel offer is conditional: “Come to me all you who are weary and burdened and I will give you rest.” The words “come to me” are in the imperative mood but there are fundamental differences. First,

The law was engraven upon the heart of man in his creation, and is therefore known to all naturally, although no other revelation were given. ” The Gentiles have the work of the law written in their hearts.” (Rom. 2:15.) The gospel is not known naturally, but is divinely revealed to the Church alone through Christ, the Mediator.

There is another major difference between them.

The law teaches us what we ought to be, and what God requires of us, but it does not give us the ability to perform it, nor does it point out the way by which we may avoid what is forbidden. But the gospel teaches us in what manner we may be made such as the law requires: for it offers unto us the promise of grace, by having the righteousness of Christ imputed to us through faith, and that in such a way as if it were properly ours, teaching us that we are just before God, through the imputation of Christ s righteousness. The law says, ” Pay what thou owest.” ” Do this, and live.” (Matt. 18:28. Luke 10:28.) The gospel says, ” Only believe.” (Mark 5:36.)

Notice please how Ursinus relates law and gospel in this instance. Both the law and the gospel “teach” us something but they teach us different things. The law teaches what is required but does not offer anything. The gospel teaches not what God demands but how we may be righteous before God. This is the distinction between “do” and “done.”

There are other ways in which the law and the gospel are similar and distinct. The law has promises. It promises life to those who obey it perfectly. The gospel also has promises, but it promises life to those who trust in the person and work of the Substitute, Jesus. To sinners, the law, relative to justification, only kills. The gospel, relative to sinners gives life. As Ursinus says, “they differ in their effects.”

The imperative “believe in Christ and in his finished work” is a gospel imperative. Ursinus acknowledged that the law requires a general sort of belief, “by requiring us to give credit to all the divine promises, precepts and denunciations, and that with a threatening of punishment, unless we do it” but the gospel imperative urges us to trust, receive, and rest in Christ and his finished work and out of that faith to “commence new obedience.” The gospel imperative “commands us expressly and particularly to embrace, by faith, the promise of grace.”

Thus, “do” and “believe” are both commands but they have different conditions and promises. This is why Witsius reminded us that faith is called a “condition” only improperly. Properly it is, as the Belgic Confession says, the “instrument” of justification. Faith is fundamentally a different response to the imperative “believe” than “obedience” is to the command “do.”

The response to the command “believe” is to trust in the finished work of Christ. The answer to the imperative is to rest in and Christ and to receive him alone for righteousness (WCF 11; HC 21, 60; BC 22-24). The object of law-keeping is my obedience. This doesn’t fundamentally change if we substitute the words “Spirit-wrought sanctity” or “grace and cooperation with grace.” In other words if the terms of the condition refer, in any way, to my law-keeping or my obedience, even Holy Spirit-wrought obedience by grace and cooperation with grace, we’re not talking about the gospel but rather we’re talking about the law. This is how the Reformation understood the Roman soteriology of grace and cooperation with grace and “faith formed by love.”

The object of faith, however, is Christ. The power of faith is Christ. The virtue of faith is Christ. Faith, per se, has no virtue (power). What Shepherd and the FV and the rest of the moralists do not understand (as Arminius and the Remonstrants didn’t understand) is that the moment one fills faith with virtue, one has conceded the entire Reformation. This is the point of Bob Godfrey’s essay in CJPM on sola fide v faith formed by love. The FV and the rest of that lot are selling “faith formed by love.” In contrast, the Belgic Confession 24 says explicitly that we are not justified by faith formed by love, “for by faith in Christ we are justified, even before we do good works.” In the language of the Reformation, “good works” stood for “Spirit-wrought sanctity” or “faith formed by love.”

Because they do not understand the distinction between Christ’s obedience for us alone for justification and his his work in us in sanctification, they continue to seek a way to build sanctification, Spirit-wrought sanctity and obedience, into faith in the act of justification. Having got on the papist treadmill of “covenant faithfulness” they shall never be able to get off because they have accepted a series of false premises. The Protestant refuses to get on the treadmill of grace and cooperation with grace, of justification by Spirit-wrought sanctity.

The Spirit works faith in our hearts through the preaching of the gospel. Faith is not a condition, it’s an instrument. Faith does answer a command but faith isn’t a work. It’s an anti-work because it has no inherent goodness or righteousness or power. Faith, per se, in justification is nothing. Only Christ counts in justification. 

Another way to put this is to say that what makes faith “living” in justification is not Spirit-wrought sanctity but Christ, the object of faith. This is the answer to the repeated FV demand that faith be “living:” We do not accept your definition of living as sanctity. If my justification depends upon my sanctity I shall never be justified because I shall never be perfectly sanctified. The FV solution to this problem is to take us back to the medieval doctrine of congruent merit whereby God is said to impute perfection to our best efforts (facientibus quod in se est, Deus non denegat gratiam). We reject congruent merit utterly as an insult to the finished work of Christ. BC 22 says,

to say that Christ is not enough but that something else is needed as well is a most enormous blasphemy against God– for it then would follow that Jesus Christ is only half a Savior. And therefore we justly say with Paul that we are justified “by faith alone” or by faith “apart from works.”

Jesus’ merits for us are perfect (condign). We do not stand before God in any way on the basis of anything other than the perfect righteousness of Christ imputed to us and we receive that righteousness in no other way than by faith defined as resting, receiving, or trusting Christ and in his finished work.

That’s why Protestants say “sola fide.”

You can read more about this here and in Covenant, Justification, and Pastoral Ministry.

More resources here.

Update 24 June 08: comments are closed. I don’t have time to police dozens of pro-FV comments. The HB is not a platform for the FV, for obfuscation of the gospel, fuzziness about justification or turning back the clock in the FV discussion. The URC’s Nine Points are here.