These are works such as murder, adultery, idol worship, and robbery. These are works which are good in themselves, such as fasting, giving money, and feeding the poor, but which are done to call attention to oneself or to gain standing in the community.
Selfish motivation turns good works to dead works.
As responsible human beings, Christians have to work to earn a living. This responsibility extends to members of ones' own family. The scriptures commend good living works. When we do living works, we seek to bring glory to God, not to ourselves, through what we do, and we rely upon the strength and the grace of God. Some erroneously understand Paul, particularly in Romans 4, to be putting down the value of all works with regard to salvation.