Finally, precisely the same analogy forces itself upon us in the Christian doctrine of the way of salvation. The work of the Holy Spirit in the human individual is nothing less than a new birth; its aim is the revival of the entire man, in mind, soul, and body. In most men, this work takes place by a slow process, advancing step by step. This gradual course is even the rule in Christianized nations; although a decisive change of mind often enough, though by no means always, takes place in marked epochs of the inner history of life. And in all Christians--even in those whose conversion takes place by a sudden awakening, like that of Paul--the {375} transformation of the entire man into the similarity of Christ, and the full restoration of the image of God, is certainly a process of development, and must await its completion in the resurrection. This view is also confirmed by the Lord's parable of the seed, growing up imperceptibly. Every believing Christian knows these facts, and judges and acts according to them: therefore, when in the realm of nature, which God certainly submitted to the free investigation of the human mind, he meets similar views, what right has he to protest against them as being hostile to religion? Sec. 6. _Eschatology._ In our discussion of the preceding questions, we have seen that an entirely neutral, not to say friendly, relationship is taking place between religion and the theories of development, which will continue so long as the latter keep within the limits of their proper realm, the perception of nature; and that a hostile relation takes place, and anti-religious attacks are to be guarded against, only when a disbelieving system of metaphysics, which has grown on other ground, in an uncalled-for way, tries to connect itself closely with the theory of descent. This is in an eminent degree the case with the great eschatological hopes of Christianity. The evolution theory so exclusively contents itself with the attempts at perceiving the causal circumstances of organisms in the _present_ world, that it does not at all wish to, and cannot, express itself concerning the _end_ and _goal_ of the world and the laws and circumstances which may reign in a _future aeon_, and that it gives free scope to every perception of the ultimate which might come from another source. {376} On the other hand, Christian eschatology is alone able to do most essential service to the evolution theory, in case it should be verified, by giving an answer to questions to which the evolution theory tends more decidedly than any other scientific theory--namely, to the questions as to _the end of the world and mankind_, with such distinctions as no philosophy which treats of the doctrines of nature, is able to give, although natural science itself demands the answer to these questions the more peremptorily, the higher the points of view are to which it leads us.