Is revenge good or bad in the bible revenge is aloud but it’s against the law?

lets say a burglar breaks into your home kills your wife/husband and your children or threes a hit and run and your family is left dying on the street while they drive off and is caught but is let out and is a free man on a technicality etc like an temporary insanity plea or has diplomatic immunity hearing this you feel the the law has failed and want your own justice and you go out and exact your own justice your revenge is this right or wrong i believe this is a very grey area