Let us consider what Locke is actually doing [in Reasonableness of Christianity, 1695, in which Locke proposes to restore the true core of Christianity: the acceptance of Christ as the Messiah, the belief in the one God, and genuine repentance and submission to the law of Christ].
Christian doctrine as it has grown in the tradition of the church is not an arbitrary addition to the Gospel. It is the labor of generations in the attempt to find an adequate expression to the substance of faith in the historically changing economic, political, moral, and intellectual environment of Mediterranean and Western civilization.
The Christological struggles of the early centuries absorbed into this expression the Hellenistic intellectual culture, and the Scholasticism of the high Middle Ages absorbed into it the corpus Aristotelicum. In general, the history of Christian doctrine is the process by which the substance of faith is built into the civilization of man. It is a process that started in the immediate environment of Christ, and it is still going on. The precipitation of the process in the New Testament represents, for all that we know, a phase that has already advanced materially beyond the generation of Jesus' immediate followers. Locke ignores this problem of the historicity of the Christian spirit. But beyond this statement it is not easy to formulate with precision what he has actually done.
At first sight one might say that, through his return to the New Testament phase of the process, he has deliberately thrown out the intellectual civilization that has been built into the expression of the relation of man to the divine ground in his soul. That is quite true. And the ease with which Locke gets rid at one fell swoop of the whole patristic and scholastic intellectual culture has remained paradigmatic for the wholesale civilizational destruction in which the politically predominant movements of our time engage. Nevertheless, the situation is much too complicated to be covered by the brief formula of throwing out a body of tradition. Above all, this formula ignores the problem of the historical process.
A tradition is not a block that can be thrown out. One can throw out a tradition only by throwing oneself out of it. This feat, however, is not so simple as it looks to the naive minds that who believe they can return to a "primitive" Christianity without returning to the civilizational state of "primitive" Christians. This feat, if realized socially, would imply the complete destruction of contemporary civilization, not only under its intellectual aspects, but also economically and technologically. This is not Locke's intention.
Locke and those who follow him in his course go on to live and to participate in a civilizational environment that has been formed into the remotest wrinkles of its intellectual language by the very tradition they try to remove. Hence, the attempt to return to the earlier phase will result not in a genuine removal of tradition (which would imply the rebuilding of a civilization on a new basis) but in a far-reaching devastation of the intellectual form of contemporary civilization [termed here primitivization].
. . . . In the light of [comparisons with Warburton, Montesquieu, and Rousseau], Locke's return to the New Testament looks very much like a beginning of historical romanticism, like an early case of the return to a historical "myth" for the purpose of assuaging the disorder of the age. The common characteristic of such returns is the open or implied critique of civilization, the assumption that the substance has seeped out of its institutional and intellectual forms, the suspicion that perhaps these very forms have killed the substance, and the growing conviction that the meaning of existence can be recovered only by the destruction of the incubus.