Good works, or simply works, within Christian theology are a person's (exterior) actions or deeds, contrasting with interior qualities such as grace or faith.
The New Testament exhibits a tension between two aspects of grace: the idea that grace is from God and sufficient to cover any sin (except the Unforgivable sin) and the idea that grace does not free humans from their responsibility to behave morally.
The Protestant principle of Sola fide states that no matter what a person's action, salvation comes through faith alone. Ephesians 2:8–9 reads, "For by grace ye are saved through faith: and that not of yourselves: it is the gift of God: not of works, lest any man should boast." (KJV) According to Protestants, salvation is God's gift at God's sole prerogative. Were it achieved by works, men could take pride in their efforts toward holiness, and God's gift of grace would be diminished in contrast to man's efforts.
A more works-oriented perspective is presented by the text of James 2:1-26, which concludes that "faith without works is dead." By works the author here appears to include both acts of charity and righteousness according to the laws of the Spirit, as opposed to Mosaic Law.