conscience

Concise Bible Dictionary:

The conscious knowledge of good and evil. This resulted from the fall of Adam. He could have had no knowledge of good and evil before any evil was there. It is remarkable that the word conscience does not occur in the Old Testament In the New Testament the word is συνείδησις, lit. “joint-knowledge.” This agrees with what God said of Adam after the fall, “Behold, the man is become as one of us, to know good and evil” (Gen. 3:2222And the Lord God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever: (Genesis 3:22)). The above word occurs once in the LXX in Ecclesiastes 10:2020Curse not the king, no not in thy thought; and curse not the rich in thy bedchamber: for a bird of the air shall carry the voice, and that which hath wings shall tell the matter. (Ecclesiastes 10:20): “Curse not the king, no not in thy conscience.” This knowledge of good and evil is universal: some of the most benighted heathen, for instance, have owned that they knew such things as stealing were wrong. They are thus “a law to themselves:” their conscience bearing witness and their thoughts accusing or excusing themselves between themselves (Rom. 2:14-1514For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: 15Which show the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;) (Romans 2:14‑15)). The law gave more light as to what was right and wrong: Paul said, “I had not had conscience also of lust unless the law had said, Thou shalt not lust” (Rom. 7:77What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet. (Romans 7:7)). Christianity brings the conscience into the light of God, fully revealed by His word; the believer is thus exercised to have a conscience void of offense towards God and men. This may be called a “tender conscience” (Acts 24:1616And herein do I exercise myself, to have always a conscience void of offence toward God, and toward men. (Acts 24:16)).
Scripture speaks of :
2. A “pure conscience,” which is characterized by the separation from evil (1 Tim. 3:99Holding the mystery of the faith in a pure conscience. (1 Timothy 3:9)).
4. A “purged conscience.” Through faith in the infinite efficacy of the blood of Christ the believer has no more conscience of sins. This does not mean no consciousness of ever sinning, but that as regards imputation of sins before God, the conscience is purged. Paul speaks of some who have a “defiled mind and conscience” (Titus 1:1515Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled. (Titus 1:15)); and of others who in departing from the faith have their “conscience seared with a hot iron” (1 Tim. 4:22Speaking lies in hypocrisy; having their conscience seared with a hot iron; (1 Timothy 4:2)), that is, a hardened conscience, insensible to that which should touch them to the quick.
Conscience, with the Christian, should be exercised in the sight of God fully revealed in Christ, and be governed by the word, otherwise, on the plea of “conscience,” many actions displeasing to God may be advocated. This is exemplified in the case of Paul before his conversion. He could say that he had lived in all good conscience before God, and yet he had been hauling men and women to prison because they were Christians. Doubtless he did it with an unoffending conscience, according as the Lord stated: “The time cometh, that whosoever killeth you will think that he doeth God service” (John 16:22They shall put you out of the synagogues: yea, the time cometh, that whosoever killeth you will think that he doeth God service. (John 16:2)). Paul’s zeal for Judaism so blinded his eyes that he was unable to recognize in his conscience the God who gave the law, and had sent His Son also; nor to see that God could act outside of it: it was an unenlightened conscience, a zeal without knowledge, by which even the Christian may be led astray.

Strong’s Dictionary of Greek Words:

Greek:
συνείδησις
Transliteration:
suneidesis
Phonic:
soon-i’-day-sis
Meaning:
from a prolonged form of 4894; co-perception, i.e. moral consciousness
KJV Usage:
conscience

From Anstey’s Doctrinal Definitions:

This is a faculty in man, acquired in the fall (Gen. 3:5-7, 225For God doth know that in the day ye eat thereof, then your eyes shall be opened, and ye shall be as gods, knowing good and evil. 6And when the woman saw that the tree was good for food, and that it was pleasant to the eyes, and a tree to be desired to make one wise, she took of the fruit thereof, and did eat, and gave also unto her husband with her; and he did eat. 7And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons. (Genesis 3:5‑7)
22And the Lord God said, Behold, the man is become as one of us, to know good and evil: and now, lest he put forth his hand, and take also of the tree of life, and eat, and live for ever: (Genesis 3:22)
), whereby he has an inherent, conscious knowledge of good and evil. The word conscience appears only once in the Old Testament (Eccl. 10:2020Curse not the king, no not in thy thought; and curse not the rich in thy bedchamber: for a bird of the air shall carry the voice, and that which hath wings shall tell the matter. (Ecclesiastes 10:20) – margin), but the fact of its presence in man is alluded to in a number of places. Proverbs 20:2727The spirit of man is the candle of the Lord, searching all the inward parts of the belly. (Proverbs 20:27), for instance, says that it works as “the candle of the Lord searching the inward parts of the belly.” (“Belly” is used as a figure to denote the deepest part of a person’s being.) It is also alluded to as “a still small voice” in man, whereby he knows right and wrong (1 Kings 19:1212And after the earthquake a fire; but the Lord was not in the fire: and after the fire a still small voice. (1 Kings 19:12)). Also, when David did something wrong, it says that his heart “smote” him (1 Sam. 24:55And it came to pass afterward, that David's heart smote him, because he had cut off Saul's skirt. (1 Samuel 24:5); Job 27:66My righteousness I hold fast, and will not let it go: my heart shall not reproach me so long as I live. (Job 27:6)). These things are the effects of the working of the conscience in men.
In the New Testament, the “conscience” is defined as that which bears witness in the thoughts and hearts of men concerning good and evil (Rom. 2:14-15; 7:714For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: 15Which show the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;) (Romans 2:14‑15)
7What shall we say then? Is the law sin? God forbid. Nay, I had not known sin, but by the law: for I had not known lust, except the law had said, Thou shalt not covet. (Romans 7:7)
). A man is able to condemn another man for his bad conduct, because he has a moral standard in himself (through his conscience) that enables him to judge what is morally right and wrong. In Romans 2:13-1513(For not the hearers of the law are just before God, but the doers of the law shall be justified. 14For when the Gentiles, which have not the law, do by nature the things contained in the law, these, having not the law, are a law unto themselves: 15Which show the work of the law written in their hearts, their conscience also bearing witness, and their thoughts the mean while accusing or else excusing one another;) (Romans 2:13‑15), Paul explains that even though the Gentiles haven’t had the Law of Moses (the Ten Commandments) given to them, they will, if they follow their conscience, “do by nature the things contained in the Law.” This is because the moral standards of God have been written in their hearts. This inward witness is “a law unto themselves.” A person, therefore, does not need a formal law telling him that it is wrong to murder, steal, and commit adultery, etc., before he knows that those things are wrong. The Creator has written on our hearts how we ought to live as responsible, moral beings, and our consciences bear witness to it.
If a man knows his doings are in accord with this inward law, his conscience is “good” (Acts 23:11And Paul, earnestly beholding the council, said, Men and brethren, I have lived in all good conscience before God until this day. (Acts 23:1); 1 Tim. 1:5, 195Now the end of the commandment is charity out of a pure heart, and of a good conscience, and of faith unfeigned: (1 Timothy 1:5)
19Holding faith, and a good conscience; which some having put away concerning faith have made shipwreck: (1 Timothy 1:19)
; Heb. 13:1818Pray for us: for we trust we have a good conscience, in all things willing to live honestly. (Hebrews 13:18); 1 Peter 3:16, 2116Having a good conscience; that, whereas they speak evil of you, as of evildoers, they may be ashamed that falsely accuse your good conversation in Christ. (1 Peter 3:16)
21The like figure whereunto even baptism doth also now save us (not the putting away of the filth of the flesh, but the answer of a good conscience toward God,) by the resurrection of Jesus Christ: (1 Peter 3:21)
), “pure” (1 Tim. 3:99Holding the mystery of the faith in a pure conscience. (1 Timothy 3:9); 2 Tim. 1:33I thank God, whom I serve from my forefathers with pure conscience, that without ceasing I have remembrance of thee in my prayers night and day; (2 Timothy 1:3)), and “void of offence” (Acts 24:1616And herein do I exercise myself, to have always a conscience void of offence toward God, and toward men. (Acts 24:16)). If what he does is not good, his conscience will be “defiled” (Titus 1:1515Unto the pure all things are pure: but unto them that are defiled and unbelieving is nothing pure; but even their mind and conscience is defiled. (Titus 1:15); 1 Cor. 8:77Howbeit there is not in every man that knowledge: for some with conscience of the idol unto this hour eat it as a thing offered unto an idol; and their conscience being weak is defiled. (1 Corinthians 8:7)) and “evil” (Heb. 10:2222Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water. (Hebrews 10:22)) and it will accuse him of his wrongs. If his life is sustained by evil deeds, his conscience will become “seared” or cauterized (1 Tim. 4:22Speaking lies in hypocrisy; having their conscience seared with a hot iron; (1 Timothy 4:2)), and he will become insensible to its accusations. Thus, at that point his conscience is no longer a reliable witness, as seen in those described in Romans 1. However, men with seared consciences are still responsible for what they do.
The gospel brings the conscience of man into the full light of God. It explains the finished work of Christ on the cross, and the person who believes the gospel of his salvation is “sealed” with the Holy Spirit (Eph. 1:1313In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that holy Spirit of promise, (Ephesians 1:13)) and is given a “purged” conscience (Heb. 9:14; 10:214How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God? (Hebrews 9:14)
2For then would they not have ceased to be offered? because that the worshippers once purged should have had no more conscience of sins. (Hebrews 10:2)
). This does not mean that the believer will no longer be conscious of sinning, but as far as the eternal judgment of his sins is concerned, he understands that it has all been taken care of in the atoning work of Christ, and his conscience is forever silenced as to this matter.