Be aware, hate has unfathomable power to ruin lives and societies.
Progress, far from consisting in change, depends on retentiveness. When change is absolute there remains no being to improve and no direction is set for possible improvement: and when experience is not retained, as among savages, infancy is perpetual. Those who cannot remember the past are condemned to repeat it. - George Santayana
There's nothing "abstract" about the Holocaust as an historic event; the abstraction in our minds and whether or not we are willing to be vigilant. "Truly I tell you, whatever you did for one of the least of these brothers and sisters of mine, you did for me" (Matthew 25:40, 45, NIV).