But Barth has said we are already lost, already miserable, already false and in damnation, and that's a stronger position than "be careful or you might be!"
The thing his opponents want to use to threaten is already totally actual, even though technically impossible, and the question of its finality is the thing Barth refuses.
He does the same with the carrot, as with the stick: our salvation is is the opposite, impossible on our terms and already actual in God's.
I now have my own copy of the translation of Barth's Gespräche for 1959-62, the library wound up with an extra and my librarians like me, and I've been taking it along on Sunday mornings to my wife's internship site.
It's very interesting reading the objections he faces in this era, especially on the question of sin. He says there's basically no other dogmatics that takes it as seriously or treats it so extensively, but because he refuses to threaten with damnation, they don't understand.
So it hit me the other day: Goa'uld technology relies on naquadah in the bloodstream, which is caused by having a symbiote, and lingers after. So obviously as a heavy metal, the naquadah is incorporated into the bone marrow, and I guess the symbiote keeps you from heavy metal poisoning that way, ... but the symbiote is small. How much naquadah can actually be carried by a symbiote, and conveyed to a host? No wonder the System Lords are seen eating other symbiotes as food.