I've been thinking a lot about the proper order of things recently, and in particular the proper order of things that should concern the Christian mind, motives, and efforts. If you randomly select several Christian denominations, you are likely to find that each one differs in what it emphasizes as "first order" principles. I don't mean "first order doctrines," although, unfortunately, those things do sometimes differ. It is less often the case, however, that you see Christians disagree that the Trinity is the most basic of Christian beliefs, followed by the definition of Christ's divinity and humanity, the personality of the Holy Spirit, and other issues directly relating to the nature of the God we worship. It makes sense that any religion that is intellectually rigorous would acknowledge the priority of defining its object of worship, not only for the positive function of understanding what it is one is worshipping, but also for the negative function of distinguishing the object of worship from alternative objects (false gods) and erroneous conceptions of the true object (heresies).
Rather, by "first order principles," I mean those aspects of Christianity that Christians like to emphasize as distinctive of their particular communion. When one moves into the questions of what such "first order beliefs" ought to be, and how those translate into the daily living of Christians in God's overarching purposes, things become quite a bit murkier. Just as Aslan counsels Jill when she is up on the mountain in Aslan's country that the signs she is to remember will not appear as clear when she is in the fog of the world below, so Christians too find that the clearest of doctrines in their intellectual consideration them become murkier when they are applied in the "darkened glass" of this present life. Or better yet, one wonders whether any systematic or universal approach is taken in the development of first order principles? What are the prerequisite principles God has given for us to know as Christians, in order that we may properly integrate all that God has revealed to us, and for the purposes He has given us to follow, obediently?
The following is my attempt to identify and explicate three basic prerequisites of consistent Christianity that are consonant with a Biblical understanding of reality, and therefore are necessary and sufficient for propagating a healthy Church in the midst of a world full of alternatives and errors that will ultimately undermine Christianity and destroy the health of the Church. Let's call these "principles of the first order."
1. Scriptural Presuppositionalism. The first principle has been a facet of the Reformation tradition from the beginning, but has been most explicitly formulated of late by Cornelius Van Til and Gordon Clark in the field of apologetics. Scriptural Presuppositionalism is a first order principle because it precludes the adulteration of God's revelation to man. Unless one begins and ends one's thoughts upon the authority and content of Scripture, one will have an alternative and competitive authority in its place. Christ is clear that one cannot serve two masters, and that man is to live by every word that proceeds from God (Matt. 6:24 and Matt. 4:4, respectively). If one does not begin and end with Scripture, then there is another master he serves and another word he lives by, whether wholly or in part. This first order principle corresponds to the philosophical category of epistemology, or what concerns knowledge.
2. Theonomic Ethics. The second principle has also been around at least since the Reformation, and even the major opponents of the capital "T" theonomy (e.g. Meredith Kline) acknowledge that the Westminster Confession of Faith is a theonomic document. I don't think it is necessary to have a fully developed jurisprudence based upon OT and NT law in order to fulfill the requirements of this second principle. The main point is that for the Church to thrive it must love God's law as summarized in the Ten Commandments, and wish to see others conform to God's law, whether out of genuine love, or fear of divine or divinely ordained (i.e. the State) retribution. Some may grow antsy at such a suggestion, but consider that few people (and none who are relatively powerless) would want to live in a society that did not actively seek to curtail blasphemy, disregard for authority, murder, lying, stealing, adultery, etc. Also, theonomy follows upon Scriptural Presuppositionalism by logical implication. If one's authority begins and ends with Scripture, then one's ethics and code of laws must also be Scripturally derived. What man or group of men will be capable of providing laws and a code of justice equal in wisdom and goodness to those laid down by God Himself? The Church need not agree on whether a fornicator should be executed or only pay remuneration in order to agree upon the necessity of having the State actively seek to prevent fornication. Christians who aren't theonomists seem to unwittingly acknowledge the legitimacy of theonomy in their opposition to things like State mandates for the distribution of birth control and STD vaccinations to children. Is not their presupposition that the State ought to curtail rather than enable fornication?* And the point is not to argue that laws will change hearts, save families, and make societies regenerated. But a society that honors God's law, even if only outwardly, will be a more just society than one that disdains God's law. How much more so for the Church, who is the bride of Christ and beholden to her Husband's commands? This first order principle corresponds to the philosophical category of ethics, or what concerns duties.
3. Postmillennial Eschatology. The third principle is predates the Reformation and it has been the prominent view in the Church until recent years. Like all other eschatologies it acknowledges Christ's sovereign rule and power over all principalities and powers, whereby all principalities and powers shall ultimately be subdued "under the feet" of the conquering King Jesus. The main difference is that postmillennialism further acknowledges that the Church has a direct role in the King's conquest, through the baptizing and discipling of "all nations," according to the "Great Commission" given to the disciples by Christ after His resurrections. Christ first declares that all authority is His, then, upon the basis of that authority He gives the command to disciple the nations, and finally, He ensures their success by promising His presence in their efforts "until the end of the age." That Christ shall reign until all enemies have been put under his feet (the last enemy being death) is of key importance. Interestingly, in Romans 16:20 Paul tells the Church that God will soon crush Satan under their feet! Paul seems to expect that the Spirit is working presently toward that end through the efforts of the Church, rather than forestalling conquest until a cataclysmic end-game-rescue by Christ, whether after a spiraling diminution of the Church in a increasingly sinful world, or by a relatively, but not world-wide effectual influence of the Church. The inseparability of the Head of the Church (Christ) from the Body of the Church (Christians) is another prima facie argument for postmillennialism, if you take the time to think it through. Also, one need not lapse into progressivism (the life of the Church in the world grows better and better uninterruptedly through the passage of time), or perfectionism (the Church grows more and more holy until there is no sin left, and no unbelievers, either) in order for postmillennialism to be true. Postmillennialism does not dictate the pattern of development of the Church in history intermediately, but it does indicate the long term implications of the work of the Holy Spirit in the Church and the world up to the end. This first order principle corresponds to the philosophical category of metaphysics**, or what concerns existence.
I've self-consciously limited myself to three "first-order" principles that I think are necessary for consistent Christianity and a thriving Church. If understood properly and consistently related, second order principles that might register high on various denominational lists would fall into their proper place. For example, I would argue that covenant theology is central to the proper interpretation of Scripture. Indeed, I would argue that covenant theology is what Scripture itself reveals as its basic structure for God's relationship with man. Therefore, if I accept Scriptural Presuppositionalism, it follows by logical implication that I will arrive at covenant theology. Some may wonder whether my attention to logical implication is warranted, or even supported by the principles I've outlined as "first order." Again, I think Scriptural Presuppositionalism accounts for the priority of logic in accounting for or judging what the Scriptures principally teach. What the Bible reveals about the Godhead, its use of logic in revealing God's thoughts to man, and the assertion of the priority of truth (which, though not strictly discovered by logic, is nevertheless evaluated logically for firm understanding) all make logic a necessity. I recognize that admitting as much does not guaranty that any of us will use logic properly, but I also affirm that those who take logic seriously will come to more logical conclusions than those who disdain logic, or find it largely uninteresting or irrelevant.
*Certainly some people will refrain from fornication, or at least pursue it less vigorously if the potential consequences of it were not otherwise prevented.
**Some may grow curious as to the categorization of postmillennialism as a metaphysic. Strictly speaking postmillennialism is a matter of history, which has to do with the progress of events in the world, and not the nature of the world in terms of its being. Fair enough. However, since the Bible itself rarely speaks in metaphysical terms (at least in terms of the "isness" of things), the import of considering "what the being of the world is," ought to be conceived differently. God's chief concern for man's understanding of the world seems to be its teleological purpose and the means by which God is working the world out toward that end. In other words, God doesn't tell man the "isness" of a tree, but He does tell man that he is responsible to tend and keep the tree in order to please God*** and thereby manifest His glory. Figuring out how to "tend and keep" the tree is the "physics" and knowing the nature of man's relation to the tree ("tend and keep") and his purpose in that relation ("to please God") is the "metaphysics." Teleologically speaking, postmillennialism is the doctrine of God's cosmological purpose, and cosmology is a fundamental branch of metaphysics.
***The phrase "to please God" here is kept simple for the sake of brevity and ease of understanding. There are manifest distinctions and intermediary means that lead up to this overarching end, which deserve to be contemplated thoroughly. The main point is that all of the many, many ways in which God desires us to live before Him in the world are all tied up in the purpose to bring Himself pleasure, or glory.