Thus, as said in Chapter III., though we have ample means of knowing what God is _in His relation to us_ as our Creator and Judge, yet as to His real nature we know next to nothing. Nor is this surprising when we remember that the only being who in any way resembles God is _man_; and man's nature, notwithstanding all our opportunities of studying it, still remains a mystery. Now Christianity does attempt (in its doctrine of the Trinity) to state what God is _in Himself_, and without any reference to ourselves, or to nature; and that this should be to a great extent inconceivable to our minds seems inevitable. For the nature of God must be beyond human understanding, just as the nature of a man is beyond the understanding of animals; though they may realise what he is _to them_, in his power or his kindness. And for all we know, Trinity in Unity, like omnipresence, may be one of the unique attributes of God, which cannot be understood (because it cannot be shared) by anyone else. Therefore the mysteriousness of the Christian doctrine is no reason for thinking it incredible. Nor is it inconsistent with Natural Religion, for though this shows the _Unity_ of God, it is only a unity of _outward action_. It does not, and cannot tell us what this one God is _in Himself_, whether, for instance, He exists as one or more Persons. In the same way (if we may without irreverence take a homely illustration) a number of letters might be so extremely alike as to show that they were all written by one man. But this would not tell us what the man was _in himself_, whether, for instance, he had a free will, as well as a body and mind; or how these were related to one another. Hence Natural Religion can in no way conflict with Christianity. (3.) _Its probability._ But we may go further than this, and say that the Christian doctrine of _Three_ Divine Persons is (when carefully considered) _less_ difficult to believe than the Unitarian doctrine of only _One_. For this latter leads to the conclusion, either that God must have been a solitary God dwelling alone from all eternity, before the creation of the world; or else that the world itself (or some part of it) must have been eternal, and have formed a kind of companion. And each of these theories has great difficulties. Take for instance the attributes of _Power_ and _Wisdom_, both of which, as we have seen, must of necessity belong to God. How could a solitary God dwelling alone before the Creation of the world have been able to exercise either His Power or His Wisdom? As far as we can judge, His Power could have produced nothing, His Wisdom could have thought of nothing. He would have been a _potential_ God only, with all His capacities unrealised. And such a view seems quite incredible.