Rules of Affinity


© 2012 Paul Henebury 1



What I call “The Rules of Affinity” are a relatively straightforward device whereby a theological proposition (e.g. that a sinner is justified by faith) is compared with the texts of scripture by which it is supported to disclose how closely those passages agree with the proposition in question.

Thus, a theological proposition may be adduced which has either direct “one-on-one” relation to a text of the Bible (e.g. justification by faith, or that God created the world), or strong reasons for deriving the doctrine from certain texts of the Bible (e.g. the doctrine of the Trinity); or it may have little or nothing to do with any scriptural passage brought forth to substantiate it, especially once the passage is viewed within its context (e.g. propositions such as the covenant of grace or infant baptism).

It is understood, of course, that the wrong texts may be mistakenly employed in support of a sound doctrine.  These “rules” will help ferret out such misapplications by highlighting the weak link between text and proposition.  This does not mean the proposition must be discarded automatically.  It may be that other texts of Scripture can be brought forth to fully support the doctrinal proposition.  In which case, ones scriptural case for a certain theological belief will only be bolstered.  On the other hand, if after successive attempts to align the Bible with a given doctrine fail to produce any clear relationship between them, the proposition must be held to suspect or even spurious.

A Positive and Negative Role


This means that the “Rules of Affinity” have both a positive and a negative role to play in formulating and testing doctrines.  In the first place they have a positive function because they display the biblical basis for any proffered Christian belief.  If we take the proposition above about the sinner being justified by faith, this statement can be shown to enjoy the direct corroboration of passages like Romans 5:1: “Therefore, having been justified by faith, we have peace with God through our Lord Jesus Christ.”  (cf. Rom. 3:30; Gal. 2:16; 3:24).  Therefore, our biblical foundation for this doctrine ought in the first place to be grounded in these kinds of passages.  Then other less direct but clear passages can be brought in alongside of these initial “direct” passages (e.g. Rom. 4:1-25; Gal. 3:2; Eph. 2:8-9; Jn. 20:31; Acts 15:7-9).

It should be obvious that many Bible passages support more than one doctrine.  Thus, any text may be viewed as a potential ally to a theological proposition in principle if not in actual practice.  But by passing each proposed doctrine through the “Grid of Category Formulations” set out below, it is possible to identify doctrines which have very clear biblical support from those which depend greatly upon the ingenuity of the individual proposer to tie together via subtle inferences, a proposed doctrine and the text of Scripture.  The negative application of these rules shows up propositions where a high degree of human reasoning is needed to tie the biblical text to the said proposition.  It therefore encourages the formulator of doctrine to “try again” to narrow the distance between the doctrine being proposed and the texts being appealed to.

The Usurpation of Inferred Doctrines over   Directly Stated Doctrines

One interesting and noteworthy feature of doctrines poorly supported when seen under the “Rules of Affinity” is that they quite often have a powerful effect upon those who have expended mental energy formulating them.  It is not unusual to discover major planks of certain theological schools having only threadbare support from the passages from whence they are supposed to be inferred.  In such cases it is often seen that rather than the doctrine being formulated from the ground up using the Bible it has instead been inferred from another doctrine and then the search has been made to find the requisite biblical texts to substantiate it.  More often than not it is these formulations which fair badly when tested for their affinity with the Scriptures in context.

Basic Outline of the “Rules of Affinity” and   their “Grid of Category Formulations”

In the course of recording and editing seven courses on Systematic Theology (over 200 lectures) for Veritas School of Theology, I became aware of the importance of measuring what I term the “propositional distance” between any given statement of a doctrine and the biblical passages used to support it.  I wanted a way of checking this “distance” and came up with my (now) five Categories – Category 1 through 5, or C1 to C5 for short.

The Rules of   Affinity

C1 = a doctrinal proposition based on a straightforward quotation of Scripture (e.g. special creation; justification by faith; the deity of Christ; the virgin birth; the inspiration of Scripture; the pervasiveness of sin among the human race; the one salvation through Jesus; the bodily resurrection; the physical return of Christ; heaven and hell, etc.)

C2 = a proposition based on a strong inference from the witness of several C1 passages combined, thus producing an inevitable doctrinal conclusion (e.g. the Trinity; the future kingdom of God on earth; inerrancy of Scripture; believer’s only baptism; men only eldership, etc.)

 Please note well.  C1 and C2 formulations, while they may be nuanced and improved, are non-negotiable.  The weight of direct and/or strong scriptural inference in their favor requires that they be held as “fundamental” Bible doctrines.* 


C3 = a doctrinal proposition based upon a plausible inference from the shared witness of the cumulative direction of C1 and C2 texts of Scripture (e.g. the pre-trib rapture; baptism by immersion; single or plural elders; seminal headship of Adam, etc.)

N.B. C3 formulations are inferences to the best explanation based on the evidence of various scriptures.  As such, they are defeasible.  That is, they are open to being overturned if better scriptural arguments for another position can be brought forth. 

Because C1 through C3 formulations can be measured against the clear statements of Scripture without the need for inferring one doctrine from another, these are the only “safe” categories from within which to construct a biblically based evangelical theology.


C4 = a proposition based on a theological inference usually from another doctrine instead of any plain statement of Scripture  (e.g. the covenant of grace, based on ideas like “the one people of God” and “the church as the new Israel”)

C5 = a proposition based on a theological inference which itself based on other theological inferences without reference to plain statements of Scripture (e.g. Sunday being “the Christian Sabbath” and replacing the Jewish Sabbath; infant baptism and salvation inferred from inclusion into “the covenant of grace”).

I shall expound this Grid in more detail.  For present purposes, it should be noted that since C4 and C5 formulations have a weak relation (affinity) to the texts supposed to support them, they have a weaker claim to being biblical doctrines.  Unsurprisingly though, C4’s and C5’s often carry a lot of theological clout in systems which are strongly rationalistic like Covenant Theology.   Thus, as I have said before:

Dispensationalists (who under these rules would really be “Biblical Covenantalists”) who ground their views on literal grammatico-historical interpretation ought not to traffic in C4 or C5 formulations since they are not linked to the plain sense of Scripture and have to take advantage of a theological hermeneutics at variance with the “Dispensational” system.

*A moment’s thought will bring up the question of whether it is wise to view say interpretations of the Millennium in such terms.  After all, if a Christian brother believes in the physical return of Christ but is amillennial in his understanding of eschatology, surely he is not to be considered heretical because he denies the literal earthly reign of Jesus upon this earth after the second advent?  We answer that in the case of the millennial issue, since there is neither any effect upon the message of the gospel, nor any direct attack upon the character of God, such persons should not be viewed as heretical, but simply as entertaining certain teachings based more upon human reasoning than upon the evidence of the texts of Scripture.  But in other cases, e.g. as with the doctrine of justification or the Godhead, any deviation from C1 or C2 formulations must be seen as either highly suspect or else heretical. 

It is for this reason that many Christians whose theology has weak affinity to the texts supporting it will reject these rules outright, even though in practice they will try to find those scriptures which most closely reflect their doctrines.