I was reading comments concerning a certain apostate, where many of this particular apostate's defenders wanted to include her into the camp of orthodox Christians. We all know how this goes. As long as someone can maintain the Apostle's Creed, they must be a Christian, right?
Here is the comment that got me thinking about something I think is important for our modern context.
What about the Triune God, the Incarnation, the Atonement, the
Resurrection, regeneration by the Holy Spirit, and the return of Christ?
What are you going to do with all the Christians through history who
have held to these, but not to your list? The church fathers did not see
fit to include your list in the Creeds. Were they trampling underfoot
the very Word of God?
What is interesting about this is that the Fathers didn't believe that you had to completely understand the doctrines above, but that you could not be in rebellion against them. They made room for people who were teachable but ignorant. And that should give us understanding of something that I think is often missed in these discussions: that being a Christian is evidenced in how you respond to biblical truths that conflict with your, or your culture's, own ideas.
In other words, it is more about humility and rebellion toward a biblical teaching than it is about the teaching itself. In Patristic times, Gnostic thought made up the cultural zeitgeist. Hence, one not born of the Spirit had major issues with the biblical teachings that conflicted with that zeitgeist. Yet, many biblical teachings, so long as they were in agreement with the zeitgeist, were acceptable. Hence, many Gnostics considered themselves to be Christians. But their rebellion toward those things that conflicted with their true lords, their earthly authorities of self and community, evidenced that their claim to being Christians was false.
In our day, however, these tenets only conflict if you follow our naturalistic/atheistic zeitgeist literally. For those who seek spirituality in this context, these tenets do not conflict. What does conflict are the biblical teachings that run counter to the zeitgeist concerning things like gender roles, homosexuality, hell, inclusivism, etc. Our zeitgeist fights against a God of wrath and will only accept a God of love/acceptance/permissiveness.
Hence, rebellion, and therefore, false Christianity, is not evidenced as much in a denial of the resurrection or deity of Christ, but in the repudiation of these unsavory teachings.
The Lord Himself uses all sorts of issues that aren't even doctrinally related in order to throw a light on the rebellion or humility of people (e.g., burying a father, telling them to eat his flesh and drink his blood, calling them dogs, vipers, children of the devil, etc.).
One must conclude that the Lord is doing this because that is the real issue at hand, not the specific doctrines He may teach.
If this is the case, then, actually, a denial of teachings that would get the goat of our contemporary culture might be one of the only ways to distinguish a real Christian from a false one these days. The Trinity might get my goat if I was an Arian, and the Incarnation of Christ might get my goat if I was a Gnostic; but since I am not, they don't. Instead, I'm a 21st Century American who has been heavily influenced by inclusivist, gender neutral, and sexually permissive rhetoric, and if rebellion is to rear its ugly head in my life, it is going to be when I am told to believe and practice something that conflicts with those.
In short, maybe these issues are the core of what can be understood as Christian in our day. Maybe they do make up the litmus test for us, since the test is about our dispositions toward God and His Word, not about how much we understand at any given moment on our journey toward God and His truth. Just putting it out there.