In perusing David Walsh's terrific book, you would find that he approaches the transcendent through an existential lens that is based on no particular tradition for much of the read. Until you get to one section that he titles “Christ is Center”. This is where some folks may roll their eyes, and say to themselves this has become a Trojan horse, and it's not for me. After all, “There is no stupid idea which modern man is not capable of believing, as long as he avoids believing in Christ” (Dávila).
Walsh says “the mode by which we recognize the truth of any of the revelatory traditions: their symbols resonate with and extend our own experiences. We not only confirm them, they confirm us.” We are always beginning from experience! Even Reasoning is not just information processing—it's really an existential thing. And yet “experience is only half of experience” (Goethe). If we're too closed off upon ourselves, we'll have the horizontal experience of life—without the richness that grounds and elevates it. It is only in knowing the verticality of transcendence that makes all other experience possible.
So back to the Christ is Center idea. Walsh elaborates,
“More than a teacher and a symbol pointing toward a reality, Christ is the reality itself. This is the defense of the historical Jesus. It makes all the difference in the world to realize not only that the divine suffering of evil is the path of redemption, but the fullness of that participation of the God in the suffering of evil has historically taken place.”The experience of the horizontal and vertical have been consummated through a face—and our participation in that divine nature has happened in a particular time and place; and radiates over the whole of history. “As such, it is the center from which its influence extends throughout human existence from beginning to end.”
I do believe Walsh pulls from Karl Rahner here in the move from the generic experience of the sacred to the specificity of what God has disclosed to us in the form of revelation. The experience matters, but it is also disclosed as the story that completes all stories. This does not discard other spiritual traditions. “The mystery of the plurality of sources of revelation continues even when the fullness of revelation has occurred.” Christ does not depart from these sources, but only fulfills them. If there one thing that does present us with something more complete, it is nature of God coming for us as us. The flesh and blood draws us in inwardly through his presence in time and beyond time. While the “transfiguration process is complete”, there is also “the patient unfolding of its mystery over time.”
So while the Center holds it all together, there is a plurality of symbols that extends the transcendent through all cultures and individuals within history. While the explanations may be abundant in their interpretations, “there would not even be such a phenomenon if there were not first a sense of that higher reality whose attraction draws us in its pursuit.” The drama of this recognition occurs at a point in time with Jesus, and is recapitulated in its ongoing occurrence right in this moment as Christ.