The Necessity of Self-Examination, pt. 3 by Jonathan Edwards (1703-1758)   Search me, O God, and know my heart; try me, and know my thoughts; and see if there be any wicked way in me, and lead me in the way everlasting. (Ps. 139:23-24, AV).  Section 2 Why many live in sin, and yet not know it. That the knowing whether we do not live in some way of sin is attended with difficulty, is not because the rules of judging in such a case are not plain or plentiful. God hath abundantly taught us what we ought, and what we ought not, to do; and the rules by which we are to walk are often set before us in the preaching of the word. So that the difficulty of knowing whether there be any wicked way in us, is not for want of external light, or for want of God’s having told us plainly and abundantly what are wicked ways. But that many persons live in ways which are displeasing to God, and yet are not sensible of it, may arise from the following things: 1. From the blinding deceitful nature of sin. The heart of man is full of sin and corruption, and that corruption is of an exceedingly darkening, blinding nature. Sin always carries a degree of darkness with it; and the more it prevails, the more it darkens and deludes the mind. — It is from hence that the knowing whether there be any wicked way in us is a difficult thing. The difficulty is not at all for want of light without us, not at all because the word of God is not plain, or the rules not clear; but it is because of the darkness within us. The light shines clear enough around us, but the fault is in our eyes; they are darkened and blinded by a pernicious distemper. Sin is of a deceitful nature, because, so far as it prevails, so far it gains the inclination and will, and that sways and biases the judgment. So far as any lust prevails, so far it biases the mind to approve of it. So far as any sin sways the inclination or will, so far that sin seems pleasing and good to the man; and that which is pleasing, the mind is prejudiced to think is right. — Hence when any lust hath so gained upon a man, as to get him into a sinful way or practice; it having gained his will, also prejudices his understanding. And the more irregular a man walks, the more will his mind probably be darkened and blinded, because by so much the more doth sin prevail. Hence many men who live in ways which are not agreeable to the rules of God’s word, yet are not sensible of it; and it is a difficult thing to make them so, because the same lust that leads them into that evil way, blinds them in it. — Thus, if a man live a way of malice, or envy, the more malice or envy prevails, the more will it blind his understanding to approve of it. The more a man hates his neighbour, the more will he be disposed to think that he has just cause to hate him, and that his neighbour is hateful, and deserves to be hated, and that it is not his duty to love him. So if a man live in any way of lasciviousness, the more his impure lust prevails, the more sweet and pleasant will it make the sin appear, and so the more will he be disposed and prejudiced to think there is no evil in it. So the more a man lives in a way of covetousness, or the more inordinately he desires the profits of the world the more will he think himself excusable in so doing, and the more will he think that he has a necessity of those things, and cannot do without them. And if they be necessary, then he is excusable for eagerly desiring them. The same might be shown of all the lusts which are in men’s hearts. By how much the more they prevail, by so much the more do they blind the mind, and dispose the judgment to approve of them. All lusts are deceitful lusts. “That ye put off, concerning the former conversation, the old man which is corrupt according to the deceitful lusts”  (Eph. 4:22).  And even godly men may for a time be blinded and deluded by a lust, so far as to live in a way which is displeasing to God. The lusts of men’s hearts — prejudicing them in favour of sinful practices, to which those lusts tend, and in which they delight — stir up carnal reason, and put men, with all the subtlety of which they are capable, to invent pleas and argument to justify such practices. When men are very strongly inclined and tempted to any wicked practice, and conscience troubles them about it, they will rack their brains to find out arguments to stop the mouth of conscience, and to make themselves believe that they may lawfully proceed in that practice. When men have entered upon an ill practice, and proceeded in it, then their self-love prejudices them to approve of it. Men do not love to condemn themselves; they are prejudiced in their own favour, and in favor of whatever is found in themselves. Hence they will find out good names by which to call their evil dispositions and practices; they will make them virtuous, or at least will make them innocent. Their covetousness they will call prudence and diligence in business. If they rejoice at another’s calamity, they pretend it is because they hope it will do him good, and will humble him. If they indulge in excessive drinking, it is because their constitutions require it. If they talk against and backbite their neighbor, they call it zeal against sin; it is because they would bear a testimony against such wickedness. If they set up their wills to oppose others in public affairs, then they call their willfulness conscience, or respect to the public good. — Thus they find good names for all their evil ways. Men are very apt to bring their principles to their practices, and not their practices to their principles, as they ought to do. They, in their practice, comply not with their consciences; but all their strife is to bring their consciences to comply with their practice. On the account of this deceitfulness of sin, and because we have so much sin dwelling in our hearts, it is a difficult thing to pass a true judgment on our own ways and practices. On this account we should make diligent search, and be much concerned to know whether there be not some wicked way in us. “Take heed, brethren, lest there be in any of you an evil heart of unbelief in departing from the living God. But exhort one another daily, while it is called today, lest any of you be hardened through the deceitfulness of sin” (Hebrews 3:12-13).  Men can more easily see faults in others than they can in themselves. When they see others out of the way, they will presently condemn them, when perhaps they do, or have done, the same, or the like, themselves, and in themselves justify it. Men can discern much in others eyes, better than they can beams in their own. “Every way of man is right in his own eyes” (Prov. 21:2). The heart in this matter is exceedingly deceitful. “The heart is deceitful above all things, and desperately wicked: who can know it?” (Jer. 17:9). We ought not therefore to trust in our own hearts in this matter, but to keep a jealous eye on ourselves, to pry into our own hearts and ways, and to cry to God that He would search us. “He that trusteth his own heart is a fool” (Prov. 28:26.) 2. Satan also sets in with our deceitful lusts, and labours to blind us in this matter. He is continually endeavouring to lead us into sinful ways, and sets in with carnal reason to flatter us in such ways, and to blind the conscience. He is the prince of darkness; he labours to blind and deceive; it hath been his work ever since he began it with our first parents. 3. Sometimes men are not sensible, because they are stupefied through custom. Custom in an evil practice stupefies the mind, so that it makes any way of sin, which at first was offensive to conscience, after a while, to seem harmless. 4. Sometimes persons live in ways of sin, and are not sensible of it, because they are blinded by common custom, and the examples of others. There are so many who go into the practice, and it is so common a custom, that it is esteemed little or no discredit to a man; it is little testified against. This causes some sins to appear innocent which are very displeasing to God, and abominable in His sight. Perhaps we see them practiced by those of whom we have a high esteem, by our superiors, and those who are accounted wise men. This greatly prepossesses the mind in favour of them, and takes off the sense of their evil. Or if they be observed to be commonly practiced by those who are accounted godly men, men of experience in religion, this tends greatly to harden the heart, and blind the mind with respect to any evil practice. 5. Persons are in great danger of living in ways of sin and not being sensible of it, for want of duly regarding and considering their duty in the full extent of it. There are some who hear of the necessity of reforming  from all sins, and attending all duties, and will set themselves to perform some particular duties, at the same time neglecting others. Perhaps their thoughts will be wholly taken up about religious duties, such as prayer in secret, reading the Scriptures and other good books, going to public worship and giving diligent attention, keeping the sabbath, and serious meditation. They seem to regard these things, as though they comprised their duty in its full extent, and as if this were their whole work; and moral duties towards their neighbours, their duties in the relations in which they stand, their duties as husbands or wives, as brethren or sisters, or their duties as neighbours, seem not to be considered by them. They consider not the necessity of those things: and when they hear of earnestly seeking salvation in a way of diligent attendance on all duties, they seem to leave those out of their thoughts, as if they were not meant, nor any other duties, except reading, and praying, and keeping the Sabbath, and the like. Or, if they do regard some parts of their moral duty, it may be other branches of it are not considered. Thus if they be just in their dealings, yet perhaps they neglect deeds of charity. They know they must not defraud their neighbour; they must not lie, they must not commit uncleanness; but seem not to consider what an evil it is to talk against others lightly, or to take up a reproach against them, or to contend and quarrel with them, or to live contrary to the rules of the gospel in their family-relations, or not to instruct their children or servants. Many men seem to be very conscientious in some things, in some branches of their duty on which they keep their eye, when other important branches are entirely neglected, and seem not to be noticed by them. They regard not their duty in the full extent of it.