Tamanaha's mistake

Tamanaha asserts the following:  "If non-believers make political decisions by the lights of their best moral judgments, the fact that they wrongly do not believe in the Christian story does not prevent Christians from enjoying eternal salvation. No harm done to them, at least with respect to the hereafter."

Non-believers making political decisions "by the lights of the their best moral judgments" could, just conceivably, prevent preachers from preaching, ministers from ministering, sacraments from being celebrated, monks from chanting, parents from sharing true religion with their children (e.g., Joel Feinberg's "right to an open future"), and so forth.  On some Christian theologies, I suppose, these failures would not "harm" Christians or potential Christians with respect to the hereafter.  (See Coons and Brennan, By Nature Equal (1999)).  On other Christian theologies, however, such failures just might have the consequence of either preventing people from getting to heaven or, at least, of making it more difficult for them to do so.  The recent document from the Congregation for the Doctrine of the Faith, on the importance of evangelization, certainly doesn't take the view that it is immaterial whether or not people hear the Good News.