How closely aligned do you need to be in order to sit in the same church? I was chatting with someone at a church I was speaking in many weeks ago now who was telling me about a part of the country that had several churches, all within the same small area, all splitting over (what he considered to be) varying levels of minutiae. At the other end of the spectrum, you get mixed congregations happy to sit under the same umbrella as unbelievers and those who hold to a vastly different gospel. There is often a tug-of-war between unity at all costs and schism over every minor disagreement.

It is a question that crops up even within the local church. What, exactly, are the boundaries of church membership? Do we just let in anyone – no matter how far off beam they might be doctrinally – who affirms ‘Christ is king’? Can we welcome those who differ on significant points of gospel import? If we tie matters down more tightly, what are the legitimate grounds on which to tie things down? Is it a matter of full, unadulterated assent to the 1689 LBCF or nothing – even those awkward bits about the pope as the antichrist? Do we go even further and insist unless you subscribe to our hymn book and share our view on the curtains, you can’t join us either?

We will, inevitably, draw our boundaries slightly differently. I may include some stuff you don’t as a “gospel essential”. You may include some stuff I don’t in the secondary “important for the church, if not a vital gospel issue” category that I don’t. We might both call some stuff tertiary that the other one of us puts in the secondary bracket. The point isn’t so much where we draw the lines on each given issue so much as whether we see the need to draw any such lines at all.

Since Al Mohler made his call for theological triage, others have come up with similar but nevertheless different approaches to this same issue. But the point that unites them all is that they recognise different orders of issue. There are those that write a person out of bring a believer altogether. There are those that might make it hard to join a particular local church, but don’t stop a person from being a believer. There are those that – whilst nobody would say they don’t matter at all – we can agree to disagree on them within the same local fellowship without any great harm.

If we are to avoid the being schismatic over tertiary matters, and avoid being united with those scripture says we ought not to unite with, we have to have some sense of when and where these things apply. We may parse them differently, but it is important that we do some working out of what they are and where they lie.