Suneidesis, translated as “conscience” and used 32 times in the New Testament, was introduced to the biblical lexicon by Paul. The International Standard Bible Encyclopedia defines it as, “An inner witness that testifies on the rightness or wrongness of one's actions or motives and, on the basis of them, pronounces judgment concerning the worth of the person.” Put simply, it is a person's internal moral sense.
While Paul does not provide a formal definition, what he writes in Romans 2:14-15 comes close:
For when Gentiles, who do not have the law, by nature do what the law requires, they are a law to themselves, even though they do not have the law. They show that the work of the law is written on their hearts, while their conscience also bears witness, and their conflicting thoughts accuse or even excuse them. (English Standard Version)
Conscience can be seen as a gift of God that provides human beings with the capacity for accurate self-examination, particularly when used in the light of God's truth as illustrated by I Corinthians 4:4. We should realize that it is, not a dictator of our beliefs, but a response that reflects our current values (Romans 9:1; II Corinthians 1:12; 4:2; 5:11).
Martin G. Collins
Is Your Conscience a Good Guide?