Karl Rahner’s idea of ‘anonymous Christians’ is quite the concept, but it is one that flows organically from his conception of knowledge of God as that is related to moments of existential transcendental experiences that human beings have qua human being. As Paul Molnar explains, this is why, for Rahner, all people, whether they know it or not, are anonymously Christian; because as they look inward and have a sense, a non-conceptual sense of the Divine, they are in fact experiencing or encountering the living God present to each person’s experience as that is extrapolated outward to a transcendental point of contact. Molnar writes this as he is contrasting Karl Barth’s Christ focused aapologetic knowledge of God with Molnar’s transcendental existential:
This is an enormously important point because it is false apologetics that separates the thinking of those who, like Karl Rahner, believe that they can and must begin their thinking about God with our self-transcending experiences. It is exactly for this reason that Rahner believes “we cannot begin with Jesus Christ as the absolute and final datum, but we must begin further back than that.” He thus chooses to begin with “a knowledge of God which is not mediated completely by an encounter with Jesus Christ.” He begins with our transcendental experience, which he claims mediates an “unthematic and anonymous . . . knowledge of God,” which, as seen in chapter one, both Barth and Torrance rightly rejected because such knowledge amounts only to a symbolic description of ourselves in place of the triune God. He thus claims that knowledge of God is always present unthematically to anyone reflecting on themselves, so that all talk about God “always only points to this transcendental experience as such, an experience in which he whom we call ‘God’ encounters man in silence . . . as the absolute and the incomprehensible, as the term of his transcendence.” This term of transcendence Rahner eventually calls a holy mystery because he believes that whenever this experience of transcendence is an experience of love, its term is the God of Christian revelation. It is just this thinking that leads to Rahner’s idea of “Searching Christology,” which, as seen above in chapter one, essentially refers to the fact that anyone who truly loves another, for instance, is already an “anonymous Christian” in that search. In that sense Rahner believer their activity and thinking is in line with what traditional Christology teaches. This approach to Christology presumes that we must find a basis for belief in Christ in a transcendental anthropology. This led Rahner to embrace the idea that we have an obedential potency for revelation and that our lives are marked by a “supernatural existential,” as seen in chapter one. Finally, it led him to the idea that self-acceptance is the same as accepting Christ and God himself. In this context I think one can see rather clearly that the crucial difference between Barth and Rahner is that Barth’s thinking begins and ends with the Holy Spirit as the awakening power of faith—not faith in ourselves (our transcendental dynamisms)—but in the Word of truth, namely, Jesus Christ. And that of course rules out the idea of anonymous Christianity as the projection of an idea that is at variance with what is actually revealed by Jesus himself as the Word incarnate and through his Holy Spirit as the risen and ascended Lord here and now. It also rules out any notion that we have any “potency” or capacity for the revelation of God; that we have an existential on the basis of which we can rely on ourselves in our experience of grace to speak accurately about God; and that we can look to anyone or anything other than Jesus Christ himself to know who God is and what he has done and does for us as the reconciler and redeemer.
What this insight from Molnar helps us to see, beyond Rahner’s logic towards his ‘anonymous Christian,’ is how interrelated things are theologically. We see how theological anthropology is couched in a doctrine of creation, which itself is cradled in a doctrine of God; we see how all of these converge into a discussion about how creatures can have a knowledge of God.
For Rahner the ground of knowledge of God is not the Word of God, and not even the church (which is interesting given Rahner’s Catholic status), but instead it is the shared bond and the experience therein that human beings ostensibly share as they contemplate the deeper things of life. For Barth and Torrance, as Molnar ably develops in his book, if knowledge of God is detached from the concrete given of God’s life for us in Jesus Christ, then we will look elsewhere—if we look at all—for constructing a theory of knowledge of God.
It would not be a reach, I would contend, to extrapolate out from Rahner’s more ‘modern’ Schleiermacherean like turn to the subject theologizing, and ask if other, even more ‘classically’ construed theologies engage in the same type of abstract reasoning when it comes to developing a framework wherein a theory of knowledge of God is developed; I most immediately think of Thomas Aquinas’s analogia entis (‘analogy of being’). Is there a basis, a built in-capacity, or even God-given capacity (post-salvation/conversion) within humanity wherein they can establish a holy ground to think the living God from? It isn’t just Rahner who works things out this way, I would contend that any type of ‘analogy of being’ theologizing equally ends up positing a theological-anthropology vis-à-vis their doctrine of creation that leaves room for an abstractive knowledge of God wherein the human being can habituate in a process of discursive reasoning and reach a point of contact with God that itself is untethered from God’s concrete given in Jesus Christ, the living Word of God. This is not to suggest that Thomists, for example, might arrive at an unthematic non-conceptual knowledge of God, like Rahner’s position leads to, but it is my attempt to draw a point of convergence, thematically, between the types of theological-anthropology that both Thomists and Rahnerians might affirm in regard to the belief that an abstract notion of God can be connived of apart from God’s immediate yet mediate Self-explication of Himself for us in the eternal huios, Jesus Christ.
Are there anonymous Christians? Nein.
 Paul D. Molnar, Faith, Freedom and the Spirit: The Economic Trinity in Barth, Torrance and Contemporary Theology (Downer Groves, Illinois: IVP Academic, 2015), 102-04.