For various reasons I’ve been thinking about how Christians should relate to each other around secondary doctrines. What partnerships and alliances are appropriate among Christians of different denominations, networks, or tribes? What kind of feelings and practices should characterize our attitude to those in the body of Christ with whom we have significant theological disagreements? What does it look like to handle—with integrity and transparency—personal differences of conviction that may arise with your church, boss, or institution?
These kinds of questions have been a significant part of my own denominational and theological journey over the last decade, and it is a practical issue that will always be with us. So I thought it might be helpful to share two convictions that have been brewing in me while I’ve struggled my way through it all.
At the broadest level I see two opposite dangers: doctrinal minimalism and doctrinal separatism.

Danger #1: Doctrinal Minimalism

The overall trajectory of our culture seems to tend toward doctrinal minimalism and doctrinal indifferentism (especially in my generation). Four hundred years ago if you took a different view on baptism, you may have gotten drowned. Today we rightly recoil at that response, but we often go to the opposite extreme and say, in effect, “Who cares?”
I can’t recall how many times, in discussing secondary doctrines, I have heard people say, “It’s not a gospel issue; it’s a secondary issue.” Of course we should distinguish between the gospel and secondary issues, but if we fail to press any further than this basic distinction, such a statement can obscure the significance of various secondary issues. I sometimes suspect what people really mean when they make this distinction is something like: “It’s a secondary issue; therefore it doesn’t really matter.” 
But doctrines can be “non-essential” and yet still important, and different doctrines have different kinds of importance. I find it helpful to think in terms of three kinds of doctrines, with a fourth category for issues on which no view is required or forbidden:
  • Primary doctrines
  • Secondary doctrines
  • Tertiary doctrines
  • adiaphora (“things indifferent”)
A fourfold schema like this is somewhat arbitrary, too (you could choose three or five or ten instead). But this way of framing issues enables you to recognize a spectrum of importance among non-gospel doctrines.
There are several reasons why we should not equate “secondary” with “indifferent,” and lump together everything in categories 2 to 4:
1. A high view of Scripture calls us to treasure all God has said. 
Imagine receiving a letter from your long-lost love. You would treasure every word; there’s nothing in it you would shrug at. So also if we hold to the inspiration and perspicuity of Scripture, we shouldn’t shrug at any of its contents. Even if we don’t see the immediate consequence of a certain passage, our love for the Lord who breathed it to us—and our reverence for it as his breathed Word—should compel diligent study and effort to understand. 
2. A respect for church history should help us respect what our predecessors fought over. 
When we visit a memorial or museum devoted to a historical event, we rightly pay respect for the sacrifices others have made. For example, when we visit the Normandy American Cemetery and Memorial, we remember the costliness of our current freedoms.
So with church history: If we respect the great Christian leaders of the past—from the church fathers all the way up to the modern era—we should listen carefully to why they fought so passionately over certain secondary doctrines. For instance, those who want to downplay Catholic-Protestant differences today may be somewhat jolted out of this mindset by considering the example of Anglican bishops Hugh Latimer and Nicholas Ridley and Thomas Cranmer, who were willing to be burned at the stake for their convictions on issues like transubstantiation and the nature of the Mass.
3. Many secondary doctrines are vitally related to the gospel. 
Some doctrines picture the gospel. Some protect it. Some logically flow out of it (or into it). Rare is a doctrine that can be hermetically sealed off from the rest of the Christian faith. Thus downplaying secondary doctrines can leave the primary ones blander, quieter, and more vulnerable.
4. All truth shapes how we think and live in subtle but important ways. 
I don’t believe my understanding of divine sovereignty, for instance, is a “gospel issue” in all its nuance, and I gladly welcome as brothers and sisters in Christ those who hold to an Arminian/Wesleyan view. At the same time, my understanding of God’s sovereignty has massive implications for everyday practical Christianity. For example, it affects my prayer life profoundly. So we should not shrug off issues like this as irrelevant to the gospel.

Danger #2: Doctrinal Separatism

There is, however, a danger opposite to doctrinal minimalism. To raise this point let me share some of my own story. The last 10 years have been lonely for me denominationally. I grew up in the PCA, and am greatly indebted to that wonderful denomination for the formative experience I had in it. But I landed in favor of credobaptism after intensive study on that issue, and thus became non-ordainable in the PCA. Subsequently I came to discover that I also wasn’t an ideal fit in some Baptist circles because while I affirm credobaptism, I don’t believe we should require it for church membership or the Lord’s Supper. Thus I became unacceptable in many Baptist circles as well.
Having effectively isolated myself from 98 percent of Christendom, I then further distanced myself from the majority of remaining Free and non-denominational churches by landing outside of the premillennial camp (I’m amillennial, though I don’t emphasize it).
None of these changes was particularly emotional issues for me; I had no desire to make a formal separation. I simply studied the issues and landed somewhere theologically. I sincerely miss the PCA, and I think back on my time among PCA churches and at Covenant Seminary (a PCA institution) with gratitude and a kind of nostalgia. And I regret being separated from so-called “strict Baptists” and “premillennial-only” folks, so many of whom I profoundly admire.
But I believe we must be transparent about where our convictions land, even when it leads to missed job or funding opportunities, sad relational partings, or inconvenient transitions. Some people seem to be able to “adjust” their convictions to fit into a current or prospective context; but I’m uncomfortable with that approach. I sympathize with the struggle and pain of it; and I understand the need for tact and carefulness, particularly when one is not yet fully decided. But at the end of the day, we must be honest.
I am grateful to have landed in the CCCC, which is a smaller, conservative group of Congregational churches (Lake Avenue Church in Pasadena and Park Street Church in Boston are probably the two best-known CCCC churches). CCCC has been a good fit for me theologically, and I like being part of a specific, recognizable, Protestant denomination whose roots can be traced back throughout church history (Harold John Ockenga, Jonathan Edwards, John Owen, the Savoy Declaration, and so on).
Looking back at my denominational migration, I recognize some of the partings of ways have been unavoidable—for instance, it makes sense that you need to affirm the basics of Presbyterian ecclesiology in order to a Presbyterian minister. In some other cases, though, I’ve been concerned about the danger of doctrinal separatism.

How Do We Work with Others?

So how do we decide when to partner with other Christians? This whole area is too complicated to tackle in one article, but here are four guiding questions that may be helpful:
1. What kind of partnership or unity is in view? 
There are different kinds of gospel unity: being ordained in a particular denomination is one thing; becoming a member of a local church is another; and speaking at a conference is another. We should have lower theological criteria for looser forms of partnership. 
2. What kind of partnership or unity will best serve to advance the gospel? 
This is a hard question to answer, so we should seek the Holy Spirit’s help. Our fleshly default is to trust in our own intuition and initial impression. We must instead humbly ask the Lord to give us wisdom (James 1:5). As we do so, we should remember that the fruits of separatism—church division, aloofness from how God is at work in our city, failed opportunities to “link arms” with other ministries, and so on—are not in principle less serious than the fruits of doctrinal minimalism. Errors in both directions can clog up our gospel impact.
3. Do I naturally lean toward a separatist or minimalistic spirit? 
Most of us have a particular leaning based on our temperament, background, or context. For instance, we might be naturally careful about theological clarity, but have a blind spot to the destructiveness of disunity. In the other direction, we might be horrified at the lack of love some Christians exhibit, but naïve about the effects of doctrinal erosion. We should work hard to learn what our temptation is, and then grow in our weak area.
4. Even when I must formally divide from other Christians, is the attitude of my heart gracious, humble, and inviting toward them? 
Doctrinal separatism is first and foremost a heart issue. It is easy for a spirit of self-justification to come in with our secondary distinctives. We know this is happening when we feel superior to Christians of other tribes and groups, or when a particular Christian, church, or group unduly annoys us. Thus, in the midst of our theological disagreements, we should take special care that our hearts have nothing of contempt, condescension, or undue suspicion toward those on the other side of an issue (Matt. 18:10).

Always Return to the Gospel

To do all this well, we need to continually direct our deepest level of emotional loyalty to Jesus himself. He is the one who died for us. He is the one to whom we will ultimately answer, and it his business that we are about in the first place.
As we refocus on our identity in Christ, he will help us toward that healthy, happy balance of valuing all his teaching while still embracing all his people.