Albert Barnes Commentary Ephesians 4:18

"being darkened in their understanding, alienated from the life of God, because of the ignorance that is in them, because of the hardening of their heart;" — Ephesians 4:18 (ASV)

Having the understanding darkened. This is because they were alienated from the true God, and particularly because of "the blindness of their hearts." The apostle does not say that this was a "judicial" darkening of the understanding, or that they might not have perceived the truth, or that they had no ability to understand it.

He speaks of a simple and well-known fact—a fact that is seen now as well as then—that the understanding becomes darkened by indulgence in sin. A man who is intemperate has no proper views of the government of the appetites. A man who is unchaste has no perception of the loveliness of purity.

A man who is avaricious or covetous has no proper views of the beauty of benevolence. A man who indulges in low vices will weaken his mental powers and make himself incapable of intellectual effort. Indulgence in vice destroys the intellect as well as the body, and unfits a man to appreciate the truth of a proposition in morals or mathematics, or the beauty of a poem, as well as the truth and beauty of religion.

Nothing is more obvious than that indulgence in sin weakens the mental powers and makes them unfit for high intellectual effort. This is seen all over the pagan world now—in the stolid, dull mind; the perverted moral sense; the incapacity for profound or protracted mental effort—just as truly as it was among the pagans to whom Paul preached.

The missionary who goes among such peoples has almost to create an intellect as well as a conscience before the gospel will make an impression. It is also seen in all the intellect of the bar, the senate, the pulpit, and the medical profession that is ruined by intemperance, and in the intellect of multitudes of young men wasted by licentiousness and drunkenness.

I know that under the influence of ambition and stimulating drinks, the intellect may seem to exert unnatural efforts and glow with an intensity seen nowhere else; but it soon burns out—and the remains of such an intellect quickly become like the hardened scoriae of the volcano or the cinders of an overheated furnace.

Therefore, learn that if a man wishes to be blessed with a clear understanding, he should be a good man. He who wishes a mind well-balanced and clear should fear and love God. Indeed, if Christianity had done no other good on earth than to elevate the intellect of mankind, it would have been the richest blessing ever granted to the race. It also follows that as humanity has debased its understanding by sin, it is necessary to make an effort to elevate it again. Consequently, a large part of the efforts to save people must consist in patient instruction. This explains the necessity of schools at missionary stations.

Being alienated. (See Barnes on Ephesians 2:12).

From the life of God. From a life like that of God, or a life of which He is the source and author. The meaning is that they lived a life that was unlike God, or which He could not approve. Of the truth of this, in regard to pagans everywhere, there can be no doubt. (See Barnes on Romans 1:20).

Through the ignorance that is in them. This refers to the ignorance of the true God and of what constituted virtue. (See Barnes on Romans 1:20).

Because of the blindness of their heart. The marginal note says hardness. Hardness is a better word. It is a better translation of the Greek, and it better accords with the design of the apostle.

Here the reason is stated why they lived and acted as they did, and why the understanding was blinded. It is not that God has enfeebled the human intellect by a judicial sentence on account of the sin of Adam and made it incapable of perceiving the truth. It is not that there is any deficiency or incapacity of natural powers. Nor is it that the truths of religion are so exalted that man has no natural ability to understand them, for they may be as well understood as any other truths (See Barnes on 1 Corinthians 2:14).

The simple reason is "the hardness of THE HEART." That is the solution given by an inspired apostle, and that is enough. A man who has a blind and hard heart sees no beauty in truth, feels not its force, and is insensible to all its appeals. Therefore, learn the following:

1. That people are to blame for the blindness of their understanding. Whatever proceeds from a wicked heart they are responsible for. But for mere inferiority of intellect, they would not be to blame.
2. They are under obligation to repent and love God. If it were required of them to enlarge their intellects or create additional faculties of mind, they could not be bound to do it. But where the whole thing required is to have a better heart, they may be held responsible.
3. The way to elevate the understanding of humankind is to purify the heart. The approach must be made through the affections. Let a person feel right towards God, and they will soon think right; let the heart be pure, and the understanding will be clear.