Just seems weird for Christians ITT to apparently want atheists to commit themselves to the nominalist position that Christianity has no essential teaching on moral issues like abortion, the death penalty or immigration.
Because if it is wrong to call evangelicals less true to the Christian message because they support the death penalty, and it is wrong to call evangelicals more true to Biblical teaching by virtue of a fundamentalist/literalist opposition to gay marriage (e.g.), then it seems to me that one is committing oneself to the position that Jesus would be okay with whatever, since positions on these issues have no bearing on your fidelity to what he taught. And that seems plainly untrue to me.
Christianity is a universal religion, not a cultural religion. As such, the idea that Christianity has an “inherent” position to issues which are cultural and subjective misunderstands Christianity. The lack of a clear and absolute consensus prevents me from suggesting there is such a thing. Now I can say some ideas are “better” than others - I may be wrong, though, and as such should not teach that my views are intrinsic to Christianity.