Scripture is the Reformed rule of Faith. It is our ultimate authority in matters of doctrine. It is our trusted revelation from God. When people come along claiming that their organization or prophet teaches something, we determine how true it is by comparison to Scripture.
1. Does Scripture Teach It?
In comparing someone's doctrine to Scripture, the first question we ask is whether Scripture teaches it. If Scripture teaches something, it must be believed. By "must," of course, we do not mean that a person will not be saved simply because they fail to fully reverence the teachings of Scripture, instead we mean that Scripture commands reverence, because it is God's word. On the other hand, if Scripture does not teach something, we are not required to believe it.
2. Does Scripture Teach Against It?
In comparing someone's doctrine to Scripture, the next question we ask is whether Scripture teaches AGAINST it. Sometimes we will already know the answer to this question by reference to the first question. If Scripture teaches against a doctrine, we must reject that doctrine. It is, unfortunately, a frequent mistake to skip the first question above and jump straight to the second question. Thus, some people will accept all sorts of fabricated doctrines, simply because they cannot find teaching in Scripture AGAINST the doctrine.
3. What if the answer to some particular question is not readily discernible?
Occasionally, it happens that some question may not be readily discernible. For example, in this verse:
Hebrews 12:23 To the general assembly and church of the firstborn, which are written in heaven, and to God the Judge of all, and to the spirits of just men made perfect,
it may (at first) be unclear whether "of the firstborn" is a reference to Christ (the firstborn among many brethren) or to the elect, who are God's portion for himself.
What we do is, first of all, perform historical/grammatical exegesis. In this case, looking at the situation here, we quickly discover that the "firstborn" is plural in the original and that is only English that is ambiguous.
As part of the h/g exegesis we look to the context. There we see,
Hebrews 12:24 And to Jesus the mediator of the new covenant, and to the blood of sprinkling, that speaketh better things than that of Abel.
which contains a reference to the blood sprinkling that preserved the firstborn of the Israelites, and which entitled God to them as a purchased possession. In the process, of course, we are making use of the historical connotations of "firstborn" in the Old Testament, with which the audience of this epistle is expected to be familiar.
In some cases, depending on the question, we may not be able to resolve an answer to our own satisfaction from the text. For example, someone might ask, in the verse,
Philippians 4:3 And I intreat thee also, true yokefellow, help those women which laboured with me in the gospel, with Clement also, and with other my fellowlabourers, whose names are in the book of life.
whether "Clement" is the same Clement to whom the epistles of Clement are attributed. Scripture does not seem to give an answer. Thus, we should hesitate to be dogmatic about this. Is that just throwing up our hands, or giving up on the verse? Of course not. It is simply letting the verse say what it says, and not trying to read something into it that is not there.
4. What if someone disputes a view we previously held?
We go through the same steps above. We search the Scripture to see if their contentions hold weight. We need to bear in mind that it is possible for us to make mistakes. We need to mindful of our fallibility and of the human tendency to be stubborn and thickheaded. We must not be buffeted by every wind of doctrine, but we must not refuse to submit our doctrines to God's word.
So, what if someone comes along with doctrines, whether that be the present blogger or a visiting head of state? The answer is the same: we take those doctrines to Scripture, and see whether they are something Scripture teaches or whether Scripture contradicts what they are saying. We must be careful not to give up on a difficult or seemingly ambiguous text, though we should be willing to acknowledge that not every question we may ask may find an answer in Scripture. Finally, we need to be submissive to God's word. That does not mean we must hold Scriptural doctrines loosely. Quite to contrary, we must hold them tightly! Nevertheless, we must hold all of our doctrines as open to revision, should it be shown that Scripture teaches otherwise.
May God give all of us humility to subject our doctrines to Scripture,