The truth is there is really no Dark Side to Christianity. If it is uncompassionate, unkind, bigoted, hateful, hypocritical, selfish, prideful or ignoble it is simply not Christian. To call it so is to dress a wolf in sheep’s clothing.
The sins of men aren't confined to them. They travel like ripples over water, over many generations till someone gets revenge or finds forgiveness. You and I, we are all paying for our father's sins, aren't we?