Mercy can refer both to a compassionate behavior on the part of those in power (for example, "mercy" shown by a judge toward a criminal by not punishing him (or her) her as much as he (or she) might be punished) or on the part of a compassionate third party (e.g. a trip out of "mercy" trying to treat sick children in Africa). The word is very common in several religions (for example, the mercy of God). 