5.And the light shineth in darkness. It might be objected, that the passages of Scripture in which men are called blind are so numerous and that the blindness for which they are condemned is but too well known. For in all their reasoning faculties they miserably fail. How comes it that there are so many labyrinths of errors in the world, but because men, by their own guidance, are led only to vanity and lies? But if no light appears in men, that testimony of the divinity of Christ, which the Evangelist lately mentioned, is destroyed; for that is the third step, as I have said, that in the life of men there is something more excellent than motion and breathing. The Evangelist anticipates this question, and first of all lays down this caution, that the light which was originally bestowed on men must not be estimated by their present condition; because in this corrupted and degenerate nature light has been turned into darkness. And yet he affirms that the light of understanding is not wholly extinguished; for, amidst the thick darkness of the human mind, some remaining sparks of the brightness still shine.
My readers now understand that this sentence contains two clauses; for he says that men are now widely distant from that perfectly holy nature with which they were originally endued; because their understanding, which ought to have shed light in every direction, has been plunged in darkness, and is wretchedly blinded; and that thus the glory of Christ may be said to be darkened amidst this corruption of nature. But, on the other hand, the Evangelist maintains that, in the midst of the darkness: , there are still some remains of light, which show in some degree the divine power of Christ. The Evangelist admits, therefore, that the mind of man is blinded; so that it may justly be pronounced to be covered with darkness. For he might have used a milder term, and might have said that the light is dark or cloudy; but he chose to state more distinctly how wretched our condition has become since the fall of the first man. The statement that the light shineth in darkness is not at all intended for the commendation of depraved nature, but rather for taking away every excuse for ignorance.
And the darkness did not comprehend it. Although by that small measure of light which still remains in us, the Son of God has always invited men to himself, yet the Evangelist says that this was attended by no advantage, because seeing, they did not see, (Mat_13:13.) For since man lost the favor of God, his mind is so completely overwhelmed by the thralldom of ignorance, that any portion of light which remains in it is quenched and useless. This is daily proved by experience; for all who are not regenerated by the Spirit of God possess some reason, and this is an undeniable proof that man was made not only to breathe, but to have understanding. But by that guidance of their reason they do not come to God, and do not even approach to him; so that all their understanding is nothing else than mere vanity. Hence it follows that there is no hope of the salvation of men, unless God grant new aid; for though the Son of God sheds his light upon them, they are so dull that they do not comprehend whence that light proceeds, but are carried away by foolish and wicked imaginations to absolute madness.
The light which still dwells in corrupt nature consists chiefly of two parts; for, first, all men naturally possess some seed of religion; and, secondly, the distinction between good and evil is engraven on their consciences. But what are the fruits that ultimately spring from it, except that religion degenerates into a thousand monsters of superstition, and conscience perverts every decision, so as to confound vice with virtue? In short, natural reason never will direct men to Christ; and as to their being endued with prudence for regulating their lives, or born to cultivate the liberal arts and sciences, all this passes away without yielding any advantage.
It ought to be understood that the Evangelist speaks of natural gifts only, and does not as yet say any thing about the grace of regeneration. For there are two distinct powers which belong to the Son of God: the first, which is manifested in the structure of the world and the order of nature; and the second, by which he renews and restores fallen nature. As he is the eternal Speech of God, by him the world was made; by his power all things continue to possess the life which they once received; man especially was endued with an extraordinary gift of understanding; and though by his revolt he lost the light of understanding, yet he still sees and understands, so that what he naturally possesses from the grace of the Son of God is not entirely destroyed. But since by his stupidity and perverseness he darkens the light which still dwells in him, it remains that a new office be undertaken by the Son of God, the office of Mediator, to renew, by the Spirit of regeneration, man who had been ruined. Those persons, therefore, reason absurdly and inconclusively, who refer this light, which the Evangelist mentions, to the gospel and the doctrine of salvation.