Much mischief is done in the church by a simple failure to distinguish between primary and secondary truths. Believers divide themselves into different groups, divisions open up and needless red ink is spilled.
This is how the mistake is made: Step 1: someone says "everything in the Bible is true", by which they mean "all of my interpretations of Scripture are the truth." Step 2: they draw a circle around those beliefs. Step 3: if anyone disagrees with those beliefs they are declared to be in error. Step 4: the evangelical Christian world is divided into those "with us" and "those against us" or "carnal Christians" vs "true Christians" or even "true believers (us)" and "false Christians (them)".
The consequences of this process are pride, division and unnecessary strife.
Let's call this, for want of a better title, "redneck Christianity" because it arises out of a failure - or refusal - to "get a life", to broaden one's experience base, to talk to other (true) Christians outside of one small tiny grouping, to read anything beyond the fixed or allowed texts of a narrow grouping or denomination.
Redneck Christianity is isolated in a tiny theological and cultural ghetto.
There is something laudable about redneck Christianity, particularly in step 1a: its desire to be fundamental and faithful to Scripture. Where it strays: it draws a circle around what it thinks and neglects the opinion of the rest of the (true) body of Christ, both today and historically. Redneck Christians will typically be ignorant of church history and ignorant of the rest of Christian opinion in the world today.
Primary Truths and Secondary Truths
This ghetto mentality has never been the hallmark of historic Christianity. From the very first centuries Christians have recognised that there are truths upon which all believers can - and must - agree, and truths on which we can disagree. This was the reason for the ancient creeds: the attempt to establish and defend central or essential truths, as opposed to secondary ones.
But how do we distinguish a primary truth? How do we establish what a primary, non-negotiable truth is?
(1) Is the truth repeated so many times in Scripture that to deny it is to deny Scripture? So the doctrine of creation, that God created the universe, is repeated so many times in the OT and the NT, that to deny it is to deny Scripture. Some 'truths' are presented only once in Scripture and then in such a way that certain or single interpretation has proved elusive. For example, Paul's teaching on head covering. The Holy Spirit must have his purposes in this 'ambiguity' - perhaps His purpose is to humble us.
(2) Is the truth said to be fundamental and central? The apostle John, for example, says that someone who denies that Jesus came in the flesh is antichrist (1 John 4) and not from God; and the apostle Paul calls certain doctrines "of first importance" (1 Corinthians 15).
(3) Is the truth said to be central to salvation? For example, Paul says that if you don't believe in the resurrection your faith is in vain (1 Corinthians 15).
(4) What has the church in history and today said about this doctrine? Have good Christians taken different sides? I am not here thinking of "liberal" Christians who don't take the Bible seriously, I am thinking only of the opinion of Bible-believing Christians.
Using this line of reasoning, we soon discover two interesting results
some 'truths' are relegated to secondary (by which we do not mean
unimportant) because they are rarely mentioned in Scripture, or not
said to be of first importance, and so on.
and vitally, many of the primary doctrines have secondary aspects! So
the return of Christ is primary, but exactly how he will return is
secondary. The work of the Holy Spirit in the life of a believer is
primary, but exactly how he works - for example what gifts are operating today - is disputed. So we end up with a pie chart like the one shown where the primary doctrine (shown in red) "Jesus Christ will return" has an associated secondary doctrine (shown in yellow) which is about the millennium: "he will come before" / "he will come after" / "there is no" millennium.
Crucially, if we think in these terms, we will regard as true believers all those who hold to the primary doctrines even though they differ on matters of secondary importance. We'll love them, be able to work with them and serve with them.