Surely Herrmann is right in saying that theologians of all schools may at least agree as to the general meaning of personal Christianity. "It is a communion of the soul with the living God, through the mediation of Christ. Herein is really included all that belongs to the characteristic life of Christendom—revelation and faith, conversion and the comfort of forgiveness, the joy of faith and the service of love, lonely communion with God, and life in Christian fellowship."
Our very first and greatest problem, therefore, on the positive side, in dealing with the reality of the spiritual life, is to make it clear just how the individual soul may come into undoubted communion with a living God. It needs especially to be noted that our age has come, in such preeminent degree, to scientific and moral self-consciousness, that for the men of to-day the previous easier roads into the religious life are in large degree closed. The psychological treatment, for example, of mystical experiences has made it impossible for us to take at their own estimation all kinds of ecstatic states, and we can feel no surety in these short-cuts to communion with God in a religious experience that cannot bear a rational and ethical test. With Herrmann, we have to ask those who so base their religious conviction, "how they are sure they are really aware of God Himself when they have those emotions in which their whole nature seems exalted. Our confidence in God needs other support than the recollection of such purely emotional experiences can give."
Whatever has been true for previous generations, and whatever is still true for those who have not entered fully into the consciousness of the present time—for many of us, our road to God must now be indubitably rational and ethical. It is impossible that we should rest in any religious experience that cannot so justify itself. The men of the fully modern spirit are, therefore, simply driven to find their way into a personal communion with God through facts so great that they can bear the severest rational and ethical test. And the religion that can fully satisfy the modern man must, thus, build unmistakably on the great fact-foundation of man's own rational and ethical nature, and upon a personality great enough to reveal God, and to bring indubitable conviction of God's existence and of his personal communion with the individual soul.
It is just at this point that Christianity has its supreme gift to make to the man of to-day. For the service of Christianity here is the more priceless and indispensable to the modern man, the more deeply he has entered into the modern spirit. For the deeper our moral consciousness, the greater our sense of moral need. In Herrmann's words, "We feel ourselves to be separated from God, and consequently crippled in our faith by things which troubled the ancients very little. We cannot go back to our first simple indifference to moral demands after our conscience has once been sensible of them. Above all, the knowledge that we are bound to unconditional obedience can never die away into sloth and inactivity after it has once dawned upon us. So that when we are faced by something that wants to force itself on us as a Power over our entire life, the doubt arises in our minds whether in it we really find something we can be conscientiously willing to obey unconditionally. He who is morally free will mock at a religion that is above morality just as he pities one that is beneath it. Therefore, the only God that can reveal Himself to us is one who shows Himself to us in our moral struggle as the Power to which our souls are really subject. This is what is vouchsafed to us in the revelation of God in Jesus Christ." This simply means that, for the modern man who has awakened to full moral self-consciousness, many an ancient way of approach to God is decisively closed; and if he is to come into communion with God at all, it must be by a manifestation of God great enough to make certain both the holiness of God and his forgiveness of us.
Now, it is through the witness of the New Testament writers that we find in Christ for ourselves a fact so great, so transcendent, that we come back to it again and again with calm assurance, to find in its simple presence the indubitable conviction of the spiritual world, of our own intended destiny, of God, and of his holiness and his love. Christ does not merely tell us these things—he does much more—he makes us able to believe them. He, and no other as he, searches us, humbles us, assures us, and exalts us at the same time. Only through him do we come with assurance into the great convictions, the great hopes, and the great aspirations; and these measure us as does nothing else. Only through him are we brought into living communion with the living God. If I may quote Herrmann again: "The most important thing for the man who is to submit himself to God is surely that he should be absolutely certain of the reality of God, and Jesus does establish in us, through the fact of his personal life, a certainty of God which covers every doubt. When once he has attracted us by the beauty of His Person, and made us bow before Him by its exalted character, then even amid our deepest doubts, that Person of Jesus will remain present with us as a thing incomparable, the most precious fact in history, the most precious fact our life contains." Thus, "the religious life of the Christian is inseparable from vision of the personal life of Jesus. That vision must be the Christian's constant companion, and so it is, as he finds more and more that in such vision he grasps that reality without which all else in the world is empty and desolate."
 Herrmann, Communion with God, Second English edition, p. 9.
 Op. cit. p. 36.
 Op. at. p. 63.