What are the main differences between Reformed Protestant Biblical Theology and Covenant Theology? I have mostly studied theology by people who have their views labeled as Covenant Theology, by the label makers. Recently, I have studied views of some who prefer the label, Biblical Theology.

I have noticed differences between the two but have not attempted to put those differences into words.

My question is, 'What are the main differences between Reformed Protestant Biblical Theology and Covenant Theology?'

I am not asking about Systematic Theology as this label seems to speak more about style rather than content. I am asking about differences in actual belief, not style.
Proponents of Biblical Theology do not break away from Covenant Theology, but try to attempt to preserve Covenant Theology from the dangers they see in a trend away from objective truth into subjective experience based theology. Even systematic theology (where most covenant theology has been deposited) can turn into just a set of dogmatic asserted by people who have lost the skill of honestly following the gradual revelation of and unfolding of scripture. Dispensational Theology, along with the charismatic movement, are often seen as regions where lack of objectivity festers. However, let’s remember we are talking about labels now, so whatever we say will not be true for many under each banner.

Before identifying in what sense Biblical Theology does depart from Covenant Theology, let’s set some definitions of the terms. Unlike Covenant Theology which has various founders in the reformation and puritan age, Biblical Theology is recent and has few founders. Therefore let’s go straight to the horse’s mouth:

Geerhardus Vos (1862-1949) -


  The specific character of Biblical Theology lies in this, that it discusses both the form and contents of revelation from the point of view of the revealing activity of God Himself. In other words, it deals with revelation in the active sense, as an act of God, and tries to understand and trace and describe this act, so far as this is possible to man and does not elude our finite observation. In Biblical Theology both the form and contents of revelation are considered as parts and products of a divine work. In Systematic Theology these same contents of revelation appear, but not under the aspect of the stages of a divine work; rather as the material for a human work of classifying and systematizing according to logical principles. Biblical Theology applies no other method of grouping and arranging these contents than is given in the divine economy of revelation itself.
  
  The truth of revelation, if it is to retain its divine and -absolute character at all, must be perfect from the beginning. Biblical Theology deals with it as a product of a supernatural divine activity, and is therefore bound by its own principle to maintain the perfection of revealed truth in all its stages. When, nevertheless, Biblical Theology also undertakes to show how the truth has been gradually set forth in greater fullness and clearness, these two facts can be reconciled in no other way than by assuming that the advance in revelation resembles the organic process, through which out of the perfect germ the perfect plant and flower and fruit are successively produced. (The Idea of Biblical Theology as a Science and as a Theological Discipline)


So as a method of exegesis, that is what Biblical Theology is. It is trying to find the constant unfolding truth of the Bible as presenting it in its natural history. It has a high objective aim, with due respect for the surrounding history and stage of development of each part of scripture.  Very well, I can’t imagine one covenant theologian who would not applaud the effort.

The difference cannot be attributed to this aim for this goal is not really new wit Biblical Theology. From this standpoint many covenant theologians in the 15-17 centuries held to the Biblical Theological framework. For example Jonathan Edwards wrote a word on redemption history that would be considered very similar to the proposed methods of Biblical Theology. In this work he starts with Adam and traces the gradual revelation of God’s word ‘unfolding as a flower’ and finally pointing to future prophecies to come.

Yet with someone like Edwards we can see the break. Jonathan Edwards held views about the distinction between Law and Grace that does not appeal to the leaders of Biblical Theology. For some strange reason the break is clearly seen at Princeton’s Theological Seminary, from the transition of Charles Hodge, to Geerhardus Vos, to John Murray.  John Murray, if considered a covenant theologian was near the other side of the spectrum as men like Jonathan Edwards, or Hodge, in terms of his view of the distinction between Law and Grace. Jon Murray studied under Vos as is often quoted by proponents of Biblical Theology.

To proceed with an answer to this question then, I will first very briefly show each person’s view of Law and Grace. Good, or bad, Luther holds the opposite extreme of Biblical Theology. John Owen, Jonathan Edwards and Hodge sit around the middle point. John Murray takes the other extreme.  Then I will show that under these ‘wide range’ of views distinguishing Law and Grace among the covenant theologians, Biblical Theology has sprouted as a shoot from the more ‘pro-law’ extremity of that range.  This partly explains why those who are somewhat hybrids of covenant theology, but influenced by dispensational theology, or the charismatic movement, tend to have an unsettling guttural rejection of ‘something’ in Biblical theology that they can’t define.  On the surface all is the same-same, but underneath there is a significantly different view of the Law versus Grace.

Let’s start with John Murray and works backwards to Luther:

John Murray 


  The disposition to construe the demand for obedience in the Mosaic economy as having affinity with works rather than grace arises from failure to recognize that the demand for obedience in the Mosaic covenant is principally identical with the same demand under the gospel. When we re-examine the demand for obedience in the Mosaic covenant (cf. Exodus 19:5, 6; 24:7) in the light of the relations of law and grace in the gospel, we shall discover that the complex of ideas is totally alien to a construction in terms of works as opposed to grace. Obedience belongs here no more ‘to the legal sphere of merit’3 than in the new covenant. The New Testament believer is not without law to God but under law to Christ. (Law and Grace, by John Murray)


John Murray here is not advocating justification by works, he clearly believes that you are not justified under the law. This quote only goes to show how he interprets the law, or what it means to be ‘under law’.  He, in-line with Biblical Theology sees such a strong unity with the Mosaic covenant and the Gospel that there is not as much difference between them as first imagined by earlier reformers and covenant theologians.  His view clearly departs from his predecessor at the very same University, Charles Hodge. Hodge clearly includes the Mosaic covenant to be a at least in part a renewal of the covenant of works as opposed to grace. Biblical Theology tends to limit the covenant of works with Adam see the ‘covenant of grace made’, with Abraham, renewed by Moses in the giving of The Law. Ironically they also stress the different tone of each covenant, but never really explain why because all is the same-same from the original goal of the exegesis.

Hodge –


  The law of Moses was, in the first place, a re-enactment of the 
  covenant of works. A covenant is simply a promise suspended upon a condition. The covenant of works, therefore, is nothing more than the promise of life suspended on the condition of perfect obedience. The phrase is used as a concise and convenient expression of the eternal principles of justice on which God deals with rational creatures, and which underlie all dispensations, the Adamic, Abrahamic, Mosaic and Christian. Our Lord said to the lawyer who asked what he should do to 
  inherit eternal life, “What is written in the law? How readest thou? And he answering said, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy strength, and with all thy mind; and thy neighbor as thyself. And he said unto him, Thou hast answered right, this do and thou shalt live,” Luke 10:26-28. This is the covenant of works. It is an immutable principle that where there is no sin there is no condemnation, and where there is sin there is death. This is all that those who reject the gospel have to fall back upon. It is this principle which is rendered so prominent in the Mosaic economy as to give it its character of law. Viewed under this aspect it is the ministration of condemnation and death. ( Hodge 2 Cor P75)


Notice, ‘in the first place, a re-enactment of the covenant of works’. Such a statement would never be made by a leader in the Biblical Theology framework!

Jonathan Edwards –


  Jonathan Edwards also sees the Mosaic covenant as being different from the gospel as it includes the renewal of the covenant of works that has the ministry of death and cursing, leading sinners to Christ as a harsh schoolmaster.
  
  As the law was given at Mount Sinai, so Christ delivered his evangelical doctrine, (full of blessings, and not curses,) to a multitude on a mountain. Matt. v.— (Jonathan Edwards History of Redemption, P302)
  
  I think really that the covenant that God made with the children of Israel was the covenant of works. He still held them under that covenant; that is, what is required in that covenant is to them particularly deciphered, and many additional positive commands which answer to the precept concerning the forbidden fruits and God proposes this covenant to them as the condition of his favor, and gives them to understand that none of those promises he had made could be challenged without perfect obedience: but yet gives them to understand so much of his merciful nature and his inclination to pity them and to accept of a propitiation for them, that they, finding that they could not challenge anything from those promises [on the ground] of obedience, trusted only to the mere undeserved mercy of God and were saved by grace, and expected life only of mere mercy.
  
  We are indeed now under the covenant of works so, that if we are perfectly righteous we can challenge salvation. But herein is the difference betwixt us and them: to us God has plainly declared the impossibility of obtaining life by that covenant, and lets us know that no mortal can be saved but only of mere grace, and lets us know clearly how we are made partakers of that grace. All ever since the fall were equally under the covenant of grace so far, that they were saved by it all alike, but the difference is in the revelation: the covenant of works was most clearly revealed to the Israelites, to us the covenant of grace. The church, which was then in its infant [state], could not bear a revelation of the covenant of grace in plain terms; and so with them the best way to bring them off from their own righteousness was to propose the covenant of works to them, and to renew the promise of life upon those conditions. God did with them as Christ did with the young man that asked what he should do for eternal life: Christ bids him keep the commandments. And in that sense they were under the covenant of works, that it was proposed to them as the condition of life, that they might try.  To us it is not so. The covenant of grace was indeed insinuated to them and proposed under covert, but 'twas to that they were all forced to fly. The promises seem to be so contrived as to give them to see that they can't challenge anything except they perform a perfect obedience, if God will be strict, but yet that he will of his mere mercy accept them into his favor if they perform a sincere obedience proceeding from the true love and fear of him; so that the fruits of faith are proposed instead of faith itself. But by this, none but such as had faith could hope for life; and by God's contrivance of that dispensation they were led not to depend on these as works, but as a disposition to receive, as so many manifestations of repentance and submission; and they depended on them as such only, for life. (Jonathan Edwards. The "Miscellanies". Page P363-363)
  
  With reference to what has been before spoken of the covenant [No. 2]. Covenant is taken very variously in Scripture, sometimes for a divine promise, sometimes for a divine promise on conditions. But if we speak of the covenant God has made with man stating the condition of eternal life, God never made but one with man to wit, the covenant of works; which never yet was abrogated, but is a covenant stands in full force to all eternity without the failing of one tittle. The covenant of grace is not another covenant made with man upon the abrogation of this, but a covenant made with Christ to fulfill it. And for this end came Christ into the world, to fulfill the law, or covenant of works, for all that receive him....
  
  To say that the covenant of works did admit of a mediator, is something improper. The covenant of works mentioned nothing about it; (Jonathan Edwards. The "Miscellanies". Page P217)


John Owen –

As usual John Owen teaches with the utmost clarity on the subject:


  By the sanction of the law, we intend the promises and penalties wherewith by God the observation of it and obedience unto it was enforced. This the apostle hath respect unto in sundry places of this Epistle; the principal whereof are reported in the following dissertation.
  
  To represent this distinctly, we may observe that the law falls under threefold consideration; — first, As it was a repetition and expression of the law of nature, and the covenant of works established thereon; secondly, As it had a new end and design put upon the administration of it, to direct the church unto the use and benefit of the promise given of old to Adam, and renewed unto Abraham four hundred and thirty years before; thirdly, As it was the instrument of the rule and government of the church and people of Israel with respect unto the covenant made with them in and about the land of Canaan. And in this threefold respect it had a threefold sanction. (Owens Works, Volume 17, P654)


Martin Luther –

Martin Luther never prances about with constant distinctions around words, pretending to believe something he does not, he just lays it all out there:


  Who would ever believe that these things could be mixed up so easily? There is no one so stupid that he does not recognize how definite this distinction between Law and grace is. Both the facts and the words require this distinction, for everyone understands that these words “Law” and “grace” are different as to both denotation and connotation.62 Therefore it is a monstrosity, when this distinction stands there so clearly, for the papists and the fanatics to fall into the satanic perversity of confusing the Law and grace and of changing Christ into Moses. This is why I often say that so far as the words are concerned, this doctrine of faith is very easy, and everyone can easily understand the distinction between the Law and grace; but so far as practice, life, and application are concerned, it is the most difficult thing there is. (Luther's Works Vol 26, P143-144)
  
  Now the first sermon, and doctrine, is the law of God. The second is the gospel. These two sermons are not the same. Therefore we must have a good grasp of the matter in order to know how to differentiate between them. We must know what the law is, and what the gospel is. The law commands and requires us to do certain things. The law is thus 
  directed solely to our behaviour and consists in making requirements. For God speaks through the law, saying, “Do this, avoid that, this is what I expect of you.” The gospel, however, does not preach what we are to do or to avoid. It sets up no requirements but reverses the approach of the law, does the very opposite, and says, “This is what God has done for you; he has let his Son be made flesh for you, has let him be put to death for your sake.” (Luther's Works Vol 35, P162-164)


Conclusion: Biblical Theology is a good discipline that is not opposed to Covenant Theology, however, its leaders identify with only one extreme side of those accepted under the Covenant Theology label. That bias towards 'unifying law and grace' 'more than' many under Covenant Theology, should not be seen as a result of their 'new technique' but as their internal difference of thought and dogma related to their own more narrow systematic theological framework. Having concluded this I am not criticizing Biblical Theology, it is one of several useful things to understand and appreciate the benefits that can be derived from it.