In the beginning of Roman history there is an event that is brought about ''the gods that avenge parents''.[This was the event that caused the downfall of the last Roman king at which it became a republic.] While on one hand, we do not believe in  other gods, but we are also aware that God has angels and archangels  that are appointed over certain tasks (as is brought in the Gemara). To be aware that there are Furies that will never forgive nor ever forget can be helpful to remind one that there is a Judge and there is judgment, people may think they have no responsibility to honor and obey their parents and to blame all their troubles on their parents as Saint Freud taught. And even their parents may forgive and forget. But the gods that avenge parents will never forget  nor forgive and will always collect payment- sooner or later , because they are the ''Furies''--the gods that even the gods of Mount Olympus fear. No sacrifice can appease them. No  prayer can turn away their wrath.