Under the influence of this inward operation, he experiences, to a considerable extent, new views of his own situation, of his need of a Savior, and of the restoration of his soul to God in spiritual union. The operation, which has been experienced so far, is purely intellectual. Of the necessity and value of such intellectual influences, there can be no doubt; but I believe it is generally conceded, that, in themselves alone, they do not, and cannot constitute religion. But in addition to this, we will suppose, that an effect, and perhaps a very decided effect, has been experienced in the emotive part, which in its action is subsequent to that of the intellect. The person has very pleasant emotions. The perception of new truth, as we should naturally expect, gives him happiness; and the perception of its relation to his salvation gives him still more happiness. He is very happy. He begins to speak a new language. His mouth is filled with praise. And others praise the Lord on his account.
But has such a person religion, as his friends are very desirous to believe, and are very apt to declare? He has an experience undoubtedly. We are willing to admit, that he has a valuable experience; an experience, which is naturally preparatory to religion, and is closely connected with it; and looks very much like it. But if the experience stops here, in such a manner as to constitute a merely emotional experience, and without reaching and affecting a still more inward and important part of the mind, as seems sometimes to be the case, we cannot with good reasons regard it as a truly religious experience; meaning by the terms an experience which meets the expectations and the demands of God, and which is saving. It is valuable; it is encouraging; it is closely connected with religion; but it is not the thing itself. We may perhaps designate it as a preparative or incident to religion, without being religion; and although we may thank the Lord for what it is, especially in its hopeful relations, it is still true, that the essential and indispensable element of the inward life is not there.
— edited from The Interior or Hidden Life (1844) Part 1, Chapter 16.