We can learn nothing of the gospel, except by feeling its truths– no one truth of the gospel is ever truly known and really learned, until we have tested and tried and proved it, and its power has been exercised upon us. I have heard of a naturalist, who thought himself exceedingly wise with regard to the natural history of birds, and yet he had learned all he knew in his study, and had never so much as seen a bird either flying through the air or sitting upon its perch. He was but a fool although he thought himself exceeding wise. And there are some men who like him think themselves great theologians; they might even pretend to take a doctor’s degree in divinity; and yet, if we came to the root of the matter, and asked them whether they ever saw or felt any of these things of which they talked, they would have to say, “No; I know these things in the letter, but not in the spirit; I understand them as a matter of theory, but not as things of my own consciousness and experience.” Be assured, that as the naturalist who was merely the student of other men’s observations knew nothing, so the man who pretends to religion, but has never entered into the depths and power of its doctrines, or felt the influence of them upon his heart, knows nothing whatever, and all the knowledge he pretendeth to is but varnished ignorance. There are some sciences that may be learned by the head, but the science of Christ crucified can only be learned by the heart.
Spurgeon’s Sermons (Spokane, Washington; Olive Tree Bible Software; 2010) eBook. Vol. 4, Sermon No. 223; Titled: The Evil and Its Remedy; Delivered on Sabbath Morning, November 14th, 1858.