If such an “is-ness” of Christianity exists, then explaining the endless and ongoing splintering and divisions within Christianity becomes inexplicable, perhaps even incoherent and nonsensical, particularly when you factor in the general rejection of consciousness development through time.
My understanding of the “is-ness” of Christianity is encapsulated in an augmented, non-Biblical passage from Dostoevsky’s The Brothers Karamazov:
Thou didst desire man's free love, that he should follow Thee freely into heaven, enticed and taken captive by Thee. In place of the rigid ancient law, man must hereafter with a free heart decide for himself what is good and what is evil, and with a free heart actively choose resurrection and everlasting life, having only Thy image before him as his guide.
As I have stated many times, the passage above captures what Christianity is or, at the very least, what Christianity should be, primarily because it stresses the subjective, individual, relational, personal, and freely chosen foundation of what it means to be a Christian. This foundation automatically reveals the illusion of “the Christianity” while simultaneously confirming the reality of Christianities.
Christianities because at its very core, all Christianity emerges and lives via the relationships established between the individual and Christ and, at a far deeper level, between the relationship and interactions between an individual’s true self and the Holy Ghost, implying that each personal Christianity is unique, distinctive, unrepeatable, and irreproducible in much the way every relationship between two individuals is unique, distinctive, unrepeatable, and irreproducible.
The adamant pursuit of “the Christianity” that incorporates all is a futile and misguided quest. What needs to be acknowledged and pursued instead is the reality of Christianities, of the millions of individual, personal relationships with Jesus, which form the basis of any potential commerce with other Christians.
None of this implies the automatic validity of each personal Christianity. On the contrary, Jesus remains the nexus of all personal Christianities. Any potential interlinking, connection, union, or integration with other Christianities depends heavily on recognizing Christ as the nucleus of all personal Christianities.
Christianities that reject certain aspects of freedom in favor of the ancient law stray from the “is-ness” of Jesus as the nexus of all personal Christianities. As do Christianities that superimpose His image on the milieu of complying with the laws and inversions of contemporary this-worldly correctness. Christianities that deny the development of consciousness, insist upon the supremacy of institutions over the individual relationships with Christ, downplay the significance of Heaven, Bible-thump instead of seeking direct knowledge, reduce Christianity to philosophy, and so forth, all inevitably wander away from the “is-ness” of freely choosing to allow his image serve as a guide.
A personal, individual Christianity is only valid if it is directly known. Christianities that exclusively rely upon indirect knowledge — be it in the form of theology, doctrines, scripture, tradition, etc. — or that elevate the basic principles of such knowledge over direct knowledge are drifting irretrievably away from the “is-ness” of what Christianity was from the very beginning and is unflinchingly unveiling today.
Directly-known Christianities are hard to communicate, but the essence of such direct knowledge — of such “is-ness” — is discernible, provided one remains open to such possibilities (re: reality) and understands what to look for.