More than ten years ago (can’t believe it’s been that long!), Al Mohler wrote a seminal blog post outlining what he called “theological triage.” Borrowing the term from the emergency room, Mohler discussed the need for Christians to prioritize certain doctrinal issues over others. In what can be the chaos of an emergency room, medical professionals need to know how to weigh the urgency of various patients’ needs against one another; that is, a gunshot wound should be prioritized over a sprained ankle. Similarly, in the theological world, Christians must understand the difference between (a) “first-order” doctrines—where to hold an errant position actually precludes one from being a true brother in Christ—and (b) “second-” and “third-order” doctrines—issues on which two genuine Christians can disagree and nevertheless be truly saved. In other words, we need to be able to discern the difference between bad doctrine and heresy.
All biblical doctrine is important. I would go so far as to say all biblical doctrine is essential. It’s difficult to put any doctrine into a second or third tier, because it somehow feels as if to do so is to say it’s not important. But employing theological triage doesn’t mean that everything that’s not first-order is unimportant, any more than a doctor’s prioritizing a gunshot wound necessarily thinks a sprained ankle is unimportant. But the fact remains: genuine Christians can disagree on things like the mode and recipients of baptism; but if two people disagree on the triunity of God, one is a Christian and the other isn’t.