[T]he religion historically called “Christianity” is not a “truth” that exists among and in competition with “false” non-Christian religions. “Christianity,” in fact — which is not really one thing, in any event, but only a loose designation for a diverse set of beliefs and practices and cultural forms and numerous often incongruous religions, comprised within a single but nonetheless porous hermeneutical and historical “set” — is only one limited trajectory within history’s universal narrative of divine incarnation and creaturely deification, superior in some ways to alternative trajectories, vastly inferior in many others. (A strictly Reformed theology of, say, penal substitutionary atonement is infinitely more remote from the Logos who has become incarnate in created nature and history than is, for instance, the bodhisattva ideal unfolded in the Lotus Sutra and the Bodhicaryavatara; indeed, the latter in some very real sense attests, under the veil of the unfamiliar, to the truth made present in Christ, while the former is totally antithetical to that truth and therefore pure falsehood.) 

So religious traditions that deny every single clause of the ancient Christian creeds nevertheless “in some very real sense” — real but, alas, undefined — attest to the truth of the Incarnation, while other religious traditions that affirm every single clause of the ancient Christian creeds nevertheless remain “totally antithetical to that truth.“ Good to know! (Also, the scare quotes are doing some seriously heavy lifting here.)