I have three pictures for you today to think about.
There are some transparent problems with this. For example, if you start talking about having spiritual solidarity with Muslims because all Unity is a subset of Truth, you are off the rails -- because you are denying some part of what is True in order to obtain Unity. This view of Unity and Truth doesn't actually work.
So let's try another one:
So here's the thing: if this is the reality of how the church exists in fact (and I am open to reasonable arguments against this view), why is it that we make such a big thing out of the problem of, for example, inviting T.D. Jakes to a meeting of pastors and calling him a brother in Christ? Can't we just sort of sweep him up in our confessional escape clause here and say it all comes out in the wash?
Or subsequent to that: can't we just let the Gospel Coalition work it out privately now that this thing has happened? Is it really necessary to see the calculus which gets us from the statement of the problem to the resolution of the issues -- or can we just be satisfied without all the steps to hear them say, at various times and places, "oh yeah -- we talked it all over, and we're good. #Brothers #AgreeToDisagree."
Here's my answer to both those question, and then you can have at it:
We can make a big thing of this because the church is actually tasked to be Figure #3 in spite of actually being Figure #4 -- in fact we must make a big thing of it, if we believe our Bibles as we say we do. We make a big thing out of it because what the Confession warns us about is becoming this:
Last thing today: this is the struggle which produced the confessions and the creeds. This concern about how much truth needs to be present in our unity is what caused the Church (big "C") to make creeds and confessions so that the clarity of the Gospel -- the whole Gospel, and all its necessary consequences -- can be both proclaimed and received. When we choose a path -- no matter who we are, no matter what else we have accomplished for Christ's sake in the course of out lives -- which abates the drift, above, we are doing it wrong. We are part of the problem and not part of the solution.
That said, this weekend, you personally be in the Lord's house on the Lord's day with the Lord's people where there will be some admixture of falsehood in with the truth -- but at least you will not have forsaken the fellowship of the believers, as some have already done.