In his devotional, Morning Thoughts, in the writing for October 15th Octavius Winslow describes what spiritual declension looks like:
The loss of spiritual enjoyment, not of a spiritual perception, of the loveliness and harmony of the truth shall be the symptom that betrays the true condition of the soul. The judgment shall lose none of its light, but the heart much of its fervor; the truths of revelation, especially the doctrines of grace, shall occupy the same prominent position as to their value and beauty, and yet the influence of these truths may be scarcely felt. The Word of God shall be assented to; but as the instrument of sanctification, of abasement, of nourishment, the believer may be an almost utter stranger to it; yes, he must necessarily be so, while this process of secret declension is going forward in his soul.
This incipient state of declension may not involve any lowering of the standard of holiness, and yet there shall be no ascending of the heart, no reaching forth of the mind, towards a practical conformity to that standard.
Winslow points out that one may perceive proper doctrine, even the doctrines of grace, and assent to every word of the Word, and yet may be declining in his spiritual enjoyment of God. One may maintain a holy life with no affection for our Saviour. Hence, the common call for us to have both light and heat in our Christianity is one to be considered again today; it calls for a Christ-like mind and corresponding spiritual affections.