SIN has infected every faculty of the soul as well as the body. It is impossible to take the exact dimensions of it, in its height, breadth, length, and depth. "The heart is deceitful above all things, and desperately wicked." (Jer. 17:9) Man in his natural state is altogether corrupt and polluted, both soul and body. As it is written, "there is none righteous, no, not one. There is none that understandeth, there is none that seeketh after God. They are all gone out of the way, they are altogether become unprofitable, there is none that doeth good, no not one. Their feet are swift to shed blood, destruction and misery are in their ways, and the way of peace have they not known, there is no fear of God before their eyes." (Rom. 3:10-18) What a black catalogue does the divine penman give here of the sins of fallen Man! What a true and yet dismal picture has the divine artist drawn of corrupt nature by reason of original and actual sin! He tells us there is none that understandeth! What cause is there for deep humility, self-abhorrence, and loathing! Both small and great, young and old, rich and poor, wise and foolish, king and subjects! There is none that understandeth! Man may have a knowledge of the luminaries in the heavens, of the earth, and all sciences, yet the apostle styles him a man "without understanding." The reason is, he is destitute of true knowledge; and being destitute of spiritual knowledge, he perishes like the brute beast. The apostle to the Romans speaks thus of natural man: "When they knew God they glorified him not as God, neither were thankful, but became vain in their imaginations, and their foolish heart was darkened: professing themselves to be wise, they became fools." (Rom. 1:19,21,23)
This understanding, that leading faculty of the soul, is stripped of its former glory, and covered with darkness. The great enemy of the soul has taken out the eyes of man, the eyes of his understanding. There is none that understandeth spiritual things so as to love them. With regard to the things of eternity, the natural man's mind is corrupt. The way of peace they know not. (Rom. 3:17) "Thou thoughtest that I was altogether such an one as thyself." (Ps. 50:21) "Their minds and consciences are defiled, they profess to know God, but in works they deny him, being abominable and disobedient, and unto every good work reprobate." (Titus 1:15,16) Their judgment is corrupt, and must be so, seeing their eyes are evil. Hence the scripture declares that all their actions are wrong, "There is none that doeth good, no, not one." (Ps. 14:3) Every one does that which is right in his own eyes, but wrong in the sight of God. Judges 17:6. Therefore their imaginations and reasonings must be cast down by the power of God the Holy Ghost, and brought to the obedience of Christ. "Casting down imaginations and every high thing that exalteth itself against the knowledge of God, and bringing into captivity every thought to the obedience of Christ." (2 Cor. 10:5) There is a natural ignorance in the minds of men with respect to the things of God before they are illuminated by the Holy Spirit. Hence the apostle Peter says, "they are blind and cannot see afar off." (2 Pet. 1:9) They can see far enough in temporal things, but as regards the things pertaining to their souls, they are dull and ignorant. What is the cause of so many errors in religion? Some err with regard to the blessed Trinity, others as the deity and humanity of Christ; some deny his divine--others his human nature. Again, some deny the personality of the Holy Spirit, others deny his work and operation on a sinner's soul. In fact, men untaught by him, err every step they take in divine things. We see what proficiency men make in their various professions, but how slow and dull they are in the mysteries of the kingdom. We may say of them as Christ said to his disciples, "O fools, and slow of heart to believe all that the prophets have spoken, ought not Christ to have suffered these things and to enter into his glory?" A man void of a saving knowledge of spiritual things is ignorant of God with whom he has to do daily, hourly, and every moment! He is ignorant of his attributes and perfections, he knows not that he depends upon him for his being and existence! He is ignorant of Christ, of his glorious person, of his beauty and perfection, of his love, blood, and righteousness, and of his suitability as a "Redeemer and Saviour."
So, the Holy Spirit by the mouth of the apostle emphatically declares that "the natural man receiveth not the things of the Spirit of God, they are foolishness unto him, neither can he know them for they are spiritually discerned." (1 Cor. 2:14) It is true men may talk, as the Israelites of old, about temptations, signs and miracles, to whom the Lord has not given a heart to perceive, eyes to see, and ears to hear. (Deut. 29:3,4) There is in the mind of an unregenerated man that which bends to evil, he is averse to that which is good, but acts with greatest ease in evil things. "For my people are foolish, they have not known me, they are sottish children, they have none understanding, they are wise to do evil, but to do good they have no knowledge." (Jer. 4:22) How indefatigable are men in their thoughts to devise evil, to make provision for the flesh! He will sit up day and night to scheme and plan how he may please and gratify his sensual appetite, or to oppose the truth, even to the ruin of his immortal soul. But to do anything good, or to hear anything good, how slow, how backward and unwilling he is! Neither persuasion, exhortation, nor admonition, nor law nor gospel will affect him, except it be applied by divine power to his soul. As it is natural to a gracious mind to look upward, desiring communion with God, so likewise it is natural for an unregenerated mind to tend downward as a stone, and to desire communion with Satan! The wise man says, "it is a sport for the fool to do mischief, but a man of understanding hath wisdom." (Prov. 10:23) The natural mind will try to bring down spiritual things to his natural apprehension; hence the apostle says "They change the glory of the uncorruptible God into an image made like to corruptible man." (Rom. 1:23) The natural heart and understanding of man are full of idolatry as was the Gentile world before the gospel came. How averse is the natural understanding to retain anything that is good! How toilsome for the natural man to contemplate God, or meditate on his glory and excellency! When he makes an attempt to go to a place of worship his body will be there, while his heart and affections will be absent. Perhaps he will shut his eyes with the rest of the congregation in prayer, when the eyes of his mind are open, traversing prohibited ground! "Wisdom is before him that hath understanding, but the eyes of a fool are in the ends of the earth." The reason is, because spiritual things are not his element. But how is it with the same man with regard to sinful and all natural things? His eyes and his mind are engaged in them! The apostle Peter describing such, says, "having eyes full of adultery that cannot cease from sin." That the carnal mind is corrupt we may demonstrate from the many who profess to know and understand the things of eternity, and yet are destitute of inward illumination. Being destitute of the Spirit's light, they deny the power of Godliness, and the need of that divine illumination. How few there are whose understanding is spiritually enlightened, whose eyes are opened so as to behold wonderful things in the gospel of Christ, and to pray for a greater understanding in it, in the language of David, "Open thou mine eyes that I may behold wondrous things out of thy law!" (Ps. 119:18)
A soul savingly illuminated beholds glorious things in the Word of God, and at the same time discovers much darkness and ignorance in itself. Yes, it learns by painful yet blessed experience, that it is not by dint of study, but by the teaching of God the Holy Ghost, that a true and experimental knowledge is attained in his word. Christ, by his blessed Spirit, opens the understanding of his dear disciples. "Then opened he their understanding, that they might understand the Scriptures." "And he said unto them, Thus it is written, and thus it behoveth Christ to suffer, and to rise from the dead the third day. And beginning at Moses and all the prophets, he expounded unto them in all the Scriptures the things concerning himself." And as Christ, when on earth, opened the understanding of his disciples, that they might know the Scriptures, so now Christ, by his blessed Spirit, opens the understanding of his disciples, that they may have an experimental knowledge of them. It is written in the prophets, "they shall be all taught of God." "Every man, therefore, that hath heard, and hath learned of the Father, cometh unto me." (John 6:45; Luke 24:27-46) When Peter confessed that Christ was the Son of God, Christ told him that this knowledge was not attainable by the corrupt understanding of nature, but revealed by the Father through the Holy Spirit. "Simon Peter answered and said, Thou art the Christ, the Son of the living God. And Jesus answered and said unto him, blessed art thou, Simon Barjona, for flesh and blood hath not revealed it unto thee, but my Father who is in heaven." What is the cause that so many professors make shipwreck of faith in time of temptation? Is it not for want of that heavenly illumination? Hear what the Apostle Paul says, "God shall send them strong delusion, that they should believe a lie." (2 Thess. 2:11,12) If we consider the loose walking of so many thousands who profess godliness, we may soon guess the cause, the understanding is not enlightened. How is it that they seldom think of the new birth? It proceeds from the same cause. If they are not rightly taught they do not feel the necessity of it. What is the reason that professors are so high-minded, proud, haughty, and domineering? Surely it is because their imaginations have not been cast down, their haughty spirit is not broken by the word in the hand of the Spirit. (2 Cor. 10:4,5) It is natural for men to have high thoughts of themselves, and low thoughts of God; all these things are sufficient to demonstrate the corruption of the human understanding. "Yet vain man would be wise, though he is born like a wild ass's colt." (Job 11:12)