It is interesting that you used the word "declension" in the title:
Declension means the changing of a word's form to show its grammatical role, or a downward slope and deterioration.
Did you just mean spiritual decline, or also "the changing of a word's form to show its grammatical role?" That--considering the words of scripture to be "grammatical" and not spirit--certainly has caused a decline...for even the teachers of the Word have mostly abandoned the spiritual meaning for the literary meaning.
I intended it solely as a deterioration in virtue, declining spiritual awareness, general falling away from a former consecration into worldliness and desire for pleasure and money. In some cases, such as was that which affected the Catholic Church from even the earliest centuries, was a decline into superstition and fables. It happened to Israel at the time of Christ. And it happened in the mid 19th century to all the Protestant churches throughout the world.
At a meeting of the presbytery of Philadelphia, Mr. Barnes, author of the commentary so widely used, and pastor of one of the leading churches in that city, “stated that he had been in the ministry for twenty years, and never till the last communion had he administered the ordinance without receiving more or less into the church. But now there are no awakenings, no conversions, not much apparent growth in grace in professors, and none come to his study to converse about the salvation of their souls. With the increase of business, and the brightening prospects of commerce and manufactures, there is an increase of worldly-mindedness. Thus it is with all denominations.”
In the month of February of the same year, Professor Finney, of Oberlin College, said: “We have had the facts before our minds, that, in general, the Protestant churches of our country, as such, were either apathetic or hostile to nearly all the moral reforms of the age. There are partial exceptions, yet not enough to render the fact otherwise than general. We have also another corroborative fact,—the almost universal absence of revival influence in the churches. The spiritual apathy is almost all-pervading, and is fearfully deep; so the religious press of the whole land testifies. Very extensively, church-members are becoming devotees of fashion, joining hands with the ungodly in parties of pleasure, in dancing, in festivities, etc. But we need not expand this painful subject. Suffice it that the evidence thickens and rolls heavily upon us, to show that the churches generally are becoming sadly degenerate. They have gone very far from the Lord, and he has withdrawn himself from them.”
And a writer in the Religious Telescope testified: “We have never witnessed such a general
declension as at present. Truly, the church should awake, and search into the cause of this affliction; for an affliction every one that loves Zion must view it. When we call to mind how few and far between cases of true conversion are, and the almost unparalleled impenitence and hardness of sinners, we almost involuntarily exclaim, ‘Has God forgotten to be gracious? or is the door of mercy closed?’”
Such a condition never exists without cause in the church itself. The spiritual darkness which falls upon nations, upon churches and individuals, is due, not to an arbitrary withdrawal of the merits of divine grace on the part of God, but to neglect or rejection of divine light on the part of men. As i said earlier, a striking illustration of this truth is presented in the history of the Jewish people in the time of Christ. By their devotion to the world and forgetfulness of God and his Word, their understanding had become darkened, their hearts earthly and sensual. Thus they were in ignorance concerning Messiah’s advent, and in their pride and unbelief they rejected the Redeemer. God did not even then cut off the Jewish nation from a knowledge of, or a participation in, the blessings of salvation. But those who rejected the truth lost all desire for the gift of Heaven. They had “put darkness for light, and light for darkness,” until the light which was in them became darkness; and how great was that darkness! History is repeating. The church today to a great extent has set its trust in emotionalism, and believe having a good time is equivalent to spirituality, and call it revival. The church today recognises the sin and depravity all around, but believes Caesar can make the necessary changes. They have abandoned God in favour of a human king, and respond to whatever the king says with more enthusiasm than what the Lord says. They deny this of course. Caesar apparently is God's chosen vessel.