I see that John Collins' book Did Adam and Eve Really Exist? has drawn some fire from what we might call “Confessional” circles–for wont of a better term. This is a good occasion to draw some important distinctions which are often overlooked in these debates.
I. Spare parts
I use writers as a source of spare parts. I don’t normally take the whole car as is. I don’t normally find all the car parts equally useful. Rather, when I read a book I normally cannibalize the book for spare parts, then junk the rest.
For some reason you have Christians who take the position that unless everything a writer says is useful, nothing a writer says is useful.
II. Institutional integrity
So does it matter if someone’s overall theology is sound? It matters at the institutional level. We want Christian institutions (e.g. colleges, denominations, seminaries, parachurch ministries) to preserve doctrinal fidelity. Fidelity to Scripture.
In terms of institutional membership, or the doctrinal posture of the institution, the degree of soundness, the content of the whole package, is important. 3 out of 5 is 2 too few. And individual writer can often come short in a way that's not tolerable for a Christian institution.
In terms of hiring, firing, teaching, preaching, and church discipline, there’s much more justification for taking an all-or-nothing approach.
Of course, even at this level there are certain priorities. Infant baptism and the deity of Christ are not on a par (to take one example).
To summarize: on the one hand, you can harvest lots of useful spare parts from vehicles that aren’t safe to drive.
On the other hand, it does matter what you do with the spare parts. How you reassemble the parts to create a safe vehicle.
III. Having a better alterative
When some Christians attack the real or perceived deficiencies of a writer, they think it’s sufficient to offer a sounder theological alternative. And that’s fine as far as it goes.
However, in drawing attention to what the writer does badly, they often fail to provide a superior alternative to what the writer does well.
For instance, Collins is attempting to field scientific objections to the historicity of Adam and Eve. It’s inadequate to simply attack his book on theological grounds, while leaving the scientific objections hanging in midair. If he’s doing something that needs to be done, then you, too, need to rise to the same challenge.
And this also circles back to institutional integrity. Christian institutions which don’t know how to defend their beliefs, or even refuse to defend their beliefs (as if that’s beneath them), suffer from a fatal defection rate. You can’t maintain a replacement rate, much less grow, if you just say, “We believe it because our grandparents did.”